From 71e647782764184e3aab4faffe6d99176758979f Mon Sep 17 00:00:00 2001 From: Andrey Andreev Date: Thu, 22 Mar 2018 16:48:55 +0200 Subject: [ci skip] 3.1.8 release --- user_guide/database/caching.html | 642 ++++++ user_guide/database/call_function.html | 529 +++++ user_guide/database/configuration.html | 758 +++++++ user_guide/database/connecting.html | 641 ++++++ user_guide/database/db_driver_reference.html | 1483 ++++++++++++++ user_guide/database/examples.html | 597 ++++++ user_guide/database/forge.html | 1034 ++++++++++ user_guide/database/helpers.html | 592 ++++++ user_guide/database/index.html | 514 +++++ user_guide/database/metadata.html | 614 ++++++ user_guide/database/queries.html | 658 +++++++ user_guide/database/query_builder.html | 2714 ++++++++++++++++++++++++++ user_guide/database/results.html | 1231 ++++++++++++ user_guide/database/transactions.html | 615 ++++++ user_guide/database/utilities.html | 993 ++++++++++ 15 files changed, 13615 insertions(+) create mode 100644 user_guide/database/caching.html create mode 100644 user_guide/database/call_function.html create mode 100644 user_guide/database/configuration.html create mode 100644 user_guide/database/connecting.html create mode 100644 user_guide/database/db_driver_reference.html create mode 100644 user_guide/database/examples.html create mode 100644 user_guide/database/forge.html create mode 100644 user_guide/database/helpers.html create mode 100644 user_guide/database/index.html create mode 100644 user_guide/database/metadata.html create mode 100644 user_guide/database/queries.html create mode 100644 user_guide/database/query_builder.html create mode 100644 user_guide/database/results.html create mode 100644 user_guide/database/transactions.html create mode 100644 user_guide/database/utilities.html (limited to 'user_guide/database') diff --git a/user_guide/database/caching.html b/user_guide/database/caching.html new file mode 100644 index 000000000..aac093314 --- /dev/null +++ b/user_guide/database/caching.html @@ -0,0 +1,642 @@ + + + + + + + + + + Database Caching Class — CodeIgniter 3.1.8 documentation + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +
+ + + + +
+ + + + + + +
+
+
+ +
+
+
+ +
+

Database Caching Class

+

The Database Caching Class permits you to cache your queries as text +files for reduced database load.

+
+

Important

+

This class is initialized automatically by the database +driver when caching is enabled. Do NOT load this class manually.

+
+
+

Important

+

Not all query result functions are available when you +use caching. Please read this page carefully.

+
+
+

Enabling Caching

+

Caching is enabled in three steps:

+
    +
  • Create a writable directory on your server where the cache files can +be stored.
    • +
  • Set the path to your cache folder in your +application/config/database.php file.
    • +
  • Enable the caching feature, either globally by setting the preference +in your application/config/database.php file, or manually as +described below.
    • +
+

Once enabled, caching will happen automatically whenever a page is +loaded that contains database queries.

+
+
+

How Does Caching Work?

+

CodeIgniter’s query caching system happens dynamically when your pages +are viewed. When caching is enabled, the first time a web page is +loaded, the query result object will be serialized and stored in a text +file on your server. The next time the page is loaded the cache file +will be used instead of accessing your database. Your database usage can +effectively be reduced to zero for any pages that have been cached.

+

Only read-type (SELECT) queries can be cached, since these are the only +type of queries that produce a result. Write-type (INSERT, UPDATE, etc.) +queries, since they don’t generate a result, will not be cached by the +system.

+

Cache files DO NOT expire. Any queries that have been cached will remain +cached until you delete them. The caching system permits you clear +caches associated with individual pages, or you can delete the entire +collection of cache files. Typically you’ll want to use the housekeeping +functions described below to delete cache files after certain events +take place, like when you’ve added new information to your database.

+
+
+

Will Caching Improve Your Site’s Performance?

+

Getting a performance gain as a result of caching depends on many +factors. If you have a highly optimized database under very little load, +you probably won’t see a performance boost. If your database is under +heavy use you probably will see an improved response, assuming your +file-system is not overly taxed. Remember that caching simply changes +how your information is retrieved, shifting it from being a database +operation to a file-system one.

+

In some clustered server environments, for example, caching may be +detrimental since file-system operations are so intense. On single +servers in shared environments, caching will probably be beneficial. +Unfortunately there is no single answer to the question of whether you +should cache your database. It really depends on your situation.

+
+
+

How are Cache Files Stored?

+

CodeIgniter places the result of EACH query into its own cache file. +Sets of cache files are further organized into sub-folders corresponding +to your controller functions. To be precise, the sub-folders are named +identically to the first two segments of your URI (the controller class +name and function name).

+

For example, let’s say you have a controller called blog with a function +called comments that contains three queries. The caching system will +create a cache folder called blog+comments, into which it will write +three cache files.

+

If you use dynamic queries that change based on information in your URI +(when using pagination, for example), each instance of the query will +produce its own cache file. It’s possible, therefore, to end up with +many times more cache files than you have queries.

+
+
+

Managing your Cache Files

+

Since cache files do not expire, you’ll need to build deletion routines +into your application. For example, let’s say you have a blog that +allows user commenting. Whenever a new comment is submitted you’ll want +to delete the cache files associated with the controller function that +serves up your comments. You’ll find two delete functions described +below that help you clear data.

+
+
+

Not All Database Functions Work with Caching

+

Lastly, we need to point out that the result object that is cached is a +simplified version of the full result object. For that reason, some of +the query result functions are not available for use.

+

The following functions ARE NOT available when using a cached result +object:

+
    +
  • num_fields()
    • +
  • field_names()
    • +
  • field_data()
    • +
  • free_result()
    • +
+

Also, the two database resources (result_id and conn_id) are not +available when caching, since result resources only pertain to run-time +operations.

+
+

Function Reference

+
+
+
+

$this->db->cache_on() / $this->db->cache_off()

+

Manually enables/disables caching. This can be useful if you want to +keep certain queries from being cached. Example:

+
// Turn caching on
+$this->db->cache_on();
+$query = $this->db->query("SELECT * FROM mytable");
+
+// Turn caching off for this one query
+$this->db->cache_off();
+$query = $this->db->query("SELECT * FROM members WHERE member_id = '$current_user'");
+
+// Turn caching back on
+$this->db->cache_on();
+$query = $this->db->query("SELECT * FROM another_table");
+
+
+
+
+

$this->db->cache_delete()

+

Deletes the cache files associated with a particular page. This is +useful if you need to clear caching after you update your database.

+

The caching system saves your cache files to folders that correspond to +the URI of the page you are viewing. For example, if you are viewing a +page at example.com/index.php/blog/comments, the caching system will put +all cache files associated with it in a folder called blog+comments. To +delete those particular cache files you will use:

+
$this->db->cache_delete('blog', 'comments');
+
+
+

If you do not use any parameters the current URI will be used when +determining what should be cleared.

+
+
+

$this->db->cache_delete_all()

+

Clears all existing cache files. Example:

+
$this->db->cache_delete_all();
+
+
+
+
+ + +
+
+ + + + +
+ +
+

+ © Copyright 2014 - 2018, British Columbia Institute of Technology. + Last updated on Mar 22, 2018. +

+
+ + Built with Sphinx using a theme provided by Read the Docs. + +
+
+
+ +
+ +
+ + + + + + + + + + + + + + + + + + + + + + + + \ No newline at end of file diff --git a/user_guide/database/call_function.html b/user_guide/database/call_function.html new file mode 100644 index 000000000..5a948d2a4 --- /dev/null +++ b/user_guide/database/call_function.html @@ -0,0 +1,529 @@ + + + + + + + + + + Custom Function Calls — CodeIgniter 3.1.8 documentation + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +
+ + + + +
+ + + + + + +
+
+
+ +
+
+
+ +
+

Custom Function Calls

+
+

$this->db->call_function();

+

This function enables you to call PHP database functions that are not +natively included in CodeIgniter, in a platform independent manner. For +example, let’s say you want to call the mysql_get_client_info() +function, which is not natively supported by CodeIgniter. You could +do so like this:

+
$this->db->call_function('get_client_info');
+
+
+

You must supply the name of the function, without the mysql_ +prefix, in the first parameter. The prefix is added automatically based +on which database driver is currently being used. This permits you to +run the same function on different database platforms. Obviously not all +function calls are identical between platforms, so there are limits to +how useful this function can be in terms of portability.

+

Any parameters needed by the function you are calling will be added to +the second parameter.

+
$this->db->call_function('some_function', $param1, $param2, etc..);
+
+
+

Often, you will either need to supply a database connection ID or a +database result ID. The connection ID can be accessed using:

+
$this->db->conn_id;
+
+
+

The result ID can be accessed from within your result object, like this:

+
$query = $this->db->query("SOME QUERY");
+
+$query->result_id;
+
+
+
+
+ + +
+
+ + + + +
+ +
+

+ © Copyright 2014 - 2018, British Columbia Institute of Technology. + Last updated on Mar 22, 2018. +

+
+ + Built with Sphinx using a theme provided by Read the Docs. + +
+
+
+ +
+ +
+ + + + + + + + + + + + + + + + + + + + + + + + \ No newline at end of file diff --git a/user_guide/database/configuration.html b/user_guide/database/configuration.html new file mode 100644 index 000000000..d2af1b581 --- /dev/null +++ b/user_guide/database/configuration.html @@ -0,0 +1,758 @@ + + + + + + + + + + Database Configuration — CodeIgniter 3.1.8 documentation + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +
+ + + + +
+ + + + + + +
+
+
+ +
+
+
+ +
+

Database Configuration

+

CodeIgniter has a config file that lets you store your database +connection values (username, password, database name, etc.). The config +file is located at application/config/database.php. You can also set +database connection values for specific +environments by placing database.php +in the respective environment config folder.

+

The config settings are stored in a multi-dimensional array with this +prototype:

+
$db['default'] = array(
+        'dsn'   => '',
+        'hostname' => 'localhost',
+        'username' => 'root',
+        'password' => '',
+        'database' => 'database_name',
+        'dbdriver' => 'mysqli',
+        'dbprefix' => '',
+        'pconnect' => TRUE,
+        'db_debug' => TRUE,
+        'cache_on' => FALSE,
+        'cachedir' => '',
+        'char_set' => 'utf8',
+        'dbcollat' => 'utf8_general_ci',
+        'swap_pre' => '',
+        'encrypt' => FALSE,
+        'compress' => FALSE,
+        'stricton' => FALSE,
+        'failover' => array()
+);
+
+
+

Some database drivers (such as PDO, PostgreSQL, Oracle, ODBC) might +require a full DSN string to be provided. If that is the case, you +should use the ‘dsn’ configuration setting, as if you’re using the +driver’s underlying native PHP extension, like this:

+
// PDO
+$db['default']['dsn'] = 'pgsql:host=localhost;port=5432;dbname=database_name';
+
+// Oracle
+$db['default']['dsn'] = '//localhost/XE';
+
+
+
+

Note

+

If you do not specify a DSN string for a driver that requires it, CodeIgniter +will try to build it with the rest of the provided settings.

+
+
+

Note

+

If you provide a DSN string and it is missing some valid settings (e.g. the +database character set), which are present in the rest of the configuration +fields, CodeIgniter will append them.

+
+

You can also specify failovers for the situation when the main connection cannot connect for some reason. +These failovers can be specified by setting the failover for a connection like this:

+
$db['default']['failover'] = array(
+                array(
+                        'hostname' => 'localhost1',
+                        'username' => '',
+                        'password' => '',
+                        'database' => '',
+                        'dbdriver' => 'mysqli',
+                        'dbprefix' => '',
+                        'pconnect' => TRUE,
+                        'db_debug' => TRUE,
+                        'cache_on' => FALSE,
+                        'cachedir' => '',
+                        'char_set' => 'utf8',
+                        'dbcollat' => 'utf8_general_ci',
+                        'swap_pre' => '',
+                        'encrypt' => FALSE,
+                        'compress' => FALSE,
+                        'stricton' => FALSE
+                ),
+                array(
+                        'hostname' => 'localhost2',
+                        'username' => '',
+                        'password' => '',
+                        'database' => '',
+                        'dbdriver' => 'mysqli',
+                        'dbprefix' => '',
+                        'pconnect' => TRUE,
+                        'db_debug' => TRUE,
+                        'cache_on' => FALSE,
+                        'cachedir' => '',
+                        'char_set' => 'utf8',
+                        'dbcollat' => 'utf8_general_ci',
+                        'swap_pre' => '',
+                        'encrypt' => FALSE,
+                        'compress' => FALSE,
+                        'stricton' => FALSE
+                )
+        );
+
+
+

You can specify as many failovers as you like.

+

The reason we use a multi-dimensional array rather than a more simple +one is to permit you to optionally store multiple sets of connection +values. If, for example, you run multiple environments (development, +production, test, etc.) under a single installation, you can set up a +connection group for each, then switch between groups as needed. For +example, to set up a “test” environment you would do this:

+
$db['test'] = array(
+        'dsn'   => '',
+        'hostname' => 'localhost',
+        'username' => 'root',
+        'password' => '',
+        'database' => 'database_name',
+        'dbdriver' => 'mysqli',
+        'dbprefix' => '',
+        'pconnect' => TRUE,
+        'db_debug' => TRUE,
+        'cache_on' => FALSE,
+        'cachedir' => '',
+        'char_set' => 'utf8',
+        'dbcollat' => 'utf8_general_ci',
+        'swap_pre' => '',
+        'compress' => FALSE,
+        'encrypt' => FALSE,
+        'stricton' => FALSE,
+        'failover' => array()
+);
+
+
+

Then, to globally tell the system to use that group you would set this +variable located in the config file:

+
$active_group = 'test';
+
+
+
+

Note

+

The name ‘test’ is arbitrary. It can be anything you want. By +default we’ve used the word “default” for the primary connection, +but it too can be renamed to something more relevant to your project.

+
+
+

Query Builder

+

The Query Builder Class is globally enabled or +disabled by setting the $query_builder variable in the database +configuration file to TRUE/FALSE (boolean). The default setting is TRUE. +If you are not using the +query builder class, setting it to FALSE will utilize fewer resources +when the database classes are initialized.

+
$query_builder = TRUE;
+
+
+
+

Note

+

that some CodeIgniter classes such as Sessions require Query +Builder to be enabled to access certain functionality.

+
+
+
+

Explanation of Values:

+ ++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +
Name ConfigDescription
dsnThe DSN connect string (an all-in-one configuration sequence).
hostnameThe hostname of your database server. Often this is ‘localhost’.
usernameThe username used to connect to the database.
passwordThe password used to connect to the database.
databaseThe name of the database you want to connect to.
dbdriverThe database type. ie: mysqli, postgre, odbc, etc. Must be specified in lower case.
dbprefixAn optional table prefix which will added to the table name when running +Query Builder queries. This permits multiple CodeIgniter +installations to share one database.
pconnectTRUE/FALSE (boolean) - Whether to use a persistent connection.
db_debugTRUE/FALSE (boolean) - Whether database errors should be displayed.
cache_onTRUE/FALSE (boolean) - Whether database query caching is enabled, +see also Database Caching Class.
cachedirThe absolute server path to your database query cache directory.
char_setThe character set used in communicating with the database.
dbcollat

The character collation used in communicating with the database

+
+

Note

+

Only used in the ‘mysql’ and ‘mysqli’ drivers.

+
+
swap_preA default table prefix that should be swapped with dbprefix. This is useful for distributed +applications where you might run manually written queries, and need the prefix to still be +customizable by the end user.
schemaThe database schema, defaults to ‘public’. Used by PostgreSQL and ODBC drivers.
encrypt

Whether or not to use an encrypted connection.

+
+
    +
  • ‘mysql’ (deprecated), ‘sqlsrv’ and ‘pdo/sqlsrv’ drivers accept TRUE/FALSE
    • +
  • ‘mysqli’ and ‘pdo/mysql’ drivers accept an array with the following options:
      +
    • ‘ssl_key’ - Path to the private key file
      • +
    • ‘ssl_cert’ - Path to the public key certificate file
      • +
    • ‘ssl_ca’ - Path to the certificate authority file
      • +
    • ‘ssl_capath’ - Path to a directory containing trusted CA certificates in PEM format
      • +
    • ‘ssl_cipher’ - List of allowed ciphers to be used for the encryption, separated by colons (‘:’)
      • +
    • ‘ssl_verify’ - TRUE/FALSE; Whether to verify the server certificate or not (‘mysqli’ only)
      • +
    +
    • +
+
+
compressWhether or not to use client compression (MySQL only).
strictonTRUE/FALSE (boolean) - Whether to force “Strict Mode” connections, good for ensuring strict SQL +while developing an application.
port

The database port number. To use this value you have to add a line to the database config array.

+
$db['default']['port'] = 5432;
+
+
+
+
+

Note

+

Depending on what database platform you are using (MySQL, PostgreSQL, +etc.) not all values will be needed. For example, when using SQLite you +will not need to supply a username or password, and the database name +will be the path to your database file. The information above assumes +you are using MySQL.

+
+
+
+ + +
+
+ + + + +
+ +
+

+ © Copyright 2014 - 2018, British Columbia Institute of Technology. + Last updated on Mar 22, 2018. +

+
+ + Built with Sphinx using a theme provided by Read the Docs. + +
+
+
+ +
+ +
+ + + + + + + + + + + + + + + + + + + + + + + + \ No newline at end of file diff --git a/user_guide/database/connecting.html b/user_guide/database/connecting.html new file mode 100644 index 000000000..7a60fb11c --- /dev/null +++ b/user_guide/database/connecting.html @@ -0,0 +1,641 @@ + + + + + + + + + + Connecting to your Database — CodeIgniter 3.1.8 documentation + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +
+ + + + +
+ + + + + + +
+
+
+ +
+
+
+ +
+

Connecting to your Database

+

There are two ways to connect to a database:

+
+

Automatically Connecting

+

The “auto connect” feature will load and instantiate the database class +with every page load. To enable “auto connecting”, add the word database +to the library array, as indicated in the following file:

+

application/config/autoload.php

+
+
+

Manually Connecting

+

If only some of your pages require database connectivity you can +manually connect to your database by adding this line of code in any +function where it is needed, or in your class constructor to make the +database available globally in that class.

+
$this->load->database();
+
+
+

If the above function does not contain any information in the first +parameter it will connect to the group specified in your database config +file. For most people, this is the preferred method of use.

+
+

Available Parameters

+
    +
  1. The database connection values, passed either as an array or a DSN +string.
    2. +
  2. TRUE/FALSE (boolean). Whether to return the connection ID (see +Connecting to Multiple Databases below).
    3. +
  3. TRUE/FALSE (boolean). Whether to enable the Query Builder class. Set +to TRUE by default.
    4. +
+
+
+

Manually Connecting to a Database

+

The first parameter of this function can optionally be used to +specify a particular database group from your config file, or you can +even submit connection values for a database that is not specified in +your config file. Examples:

+

To choose a specific group from your config file you can do this:

+
$this->load->database('group_name');
+
+
+

Where group_name is the name of the connection group from your config +file.

+

To connect manually to a desired database you can pass an array of +values:

+
$config['hostname'] = 'localhost';
+$config['username'] = 'myusername';
+$config['password'] = 'mypassword';
+$config['database'] = 'mydatabase';
+$config['dbdriver'] = 'mysqli';
+$config['dbprefix'] = '';
+$config['pconnect'] = FALSE;
+$config['db_debug'] = TRUE;
+$config['cache_on'] = FALSE;
+$config['cachedir'] = '';
+$config['char_set'] = 'utf8';
+$config['dbcollat'] = 'utf8_general_ci';
+$this->load->database($config);
+
+
+

For information on each of these values please see the configuration +page.

+
+

Note

+

For the PDO driver, you should use the $config[‘dsn’] setting +instead of ‘hostname’ and ‘database’:

+
+

+
$config[‘dsn’] = ‘mysql:host=localhost;dbname=mydatabase’;
+
+
+

Or you can submit your database values as a Data Source Name. DSNs must +have this prototype:

+
$dsn = 'dbdriver://username:password@hostname/database';
+$this->load->database($dsn);
+
+
+

To override default config values when connecting with a DSN string, add +the config variables as a query string.

+
$dsn = 'dbdriver://username:password@hostname/database?char_set=utf8&dbcollat=utf8_general_ci&cache_on=true&cachedir=/path/to/cache';
+$this->load->database($dsn);
+
+
+
+
+
+

Connecting to Multiple Databases

+

If you need to connect to more than one database simultaneously you can +do so as follows:

+
$DB1 = $this->load->database('group_one', TRUE);
+$DB2 = $this->load->database('group_two', TRUE);
+
+
+

Note: Change the words “group_one” and “group_two” to the specific +group names you are connecting to (or you can pass the connection values +as indicated above).

+

By setting the second parameter to TRUE (boolean) the function will +return the database object.

+
+

Note

+

When you connect this way, you will use your object name to issue +commands rather than the syntax used throughout this guide. In other +words, rather than issuing commands with:

+
+

+
$this->db->query();
+
$this->db->result();
+
etc…
+

+
You will instead use:
+

+
$DB1->query();
+
$DB1->result();
+
etc…
+
+
+
+

Note

+

You don’t need to create separate database configurations if you +only need to use a different database on the same connection. You +can switch to a different database when you need to, like this:

+
+
$this->db->db_select($database2_name);
+
+
+
+
+

Reconnecting / Keeping the Connection Alive

+

If the database server’s idle timeout is exceeded while you’re doing +some heavy PHP lifting (processing an image, for instance), you should +consider pinging the server by using the reconnect() method before +sending further queries, which can gracefully keep the connection alive +or re-establish it.

+
$this->db->reconnect();
+
+
+
+
+

Manually closing the Connection

+

While CodeIgniter intelligently takes care of closing your database +connections, you can explicitly close the connection.

+
$this->db->close();
+
+
+
+
+ + +
+
+ + + + +
+ +
+

+ © Copyright 2014 - 2018, British Columbia Institute of Technology. + Last updated on Mar 22, 2018. +

+
+ + Built with Sphinx using a theme provided by Read the Docs. + +
+
+
+ +
+ +
+ + + + + + + + + + + + + + + + + + + + + + + + \ No newline at end of file diff --git a/user_guide/database/db_driver_reference.html b/user_guide/database/db_driver_reference.html new file mode 100644 index 000000000..d7faacec6 --- /dev/null +++ b/user_guide/database/db_driver_reference.html @@ -0,0 +1,1483 @@ + + + + + + + + + + DB Driver Reference — CodeIgniter 3.1.8 documentation + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +
+ + + + +
+ + + + + + +
+
+
+ +
+
+
+ +
+

DB Driver Reference

+

This is the platform-independent base DB implementation class. +This class will not be called directly. Rather, the adapter +class for the specific database will extend and instantiate it.

+

The how-to material for this has been split over several articles. +This article is intended to be a reference for them.

+
+

Important

+

Not all methods are supported by all database drivers, +some of them may fail (and return FALSE) if the underlying +driver does not support them.

+
+
+
+class CI_DB_driver
+
+
+initialize()
+
+++ + + + + + +
Returns:TRUE on success, FALSE on failure
Return type:bool
+

Initialize database settings, establish a connection to +the database.

+
+ +
+
+db_connect($persistent = TRUE)
+
+++ + + + + + + + +
Parameters:
    +
  • $persistent (bool) – Whether to establish a persistent connection or a regular one
    • +
+
Returns:

Database connection resource/object or FALSE on failure

+
Return type:

mixed

+
+

Establish a connection with the database.

+
+

Note

+

The returned value depends on the underlying +driver in use. For example, a mysqli instance +will be returned with the ‘mysqli’ driver.

+
+
+ +
+
+db_pconnect()
+
+++ + + + + + +
Returns:Database connection resource/object or FALSE on failure
Return type:mixed
+

Establish a persistent connection with the database.

+
+

Note

+

This method is just an alias for db_connect(TRUE).

+
+
+ +
+
+reconnect()
+
+++ + + + + + +
Returns:TRUE on success, FALSE on failure
Return type:bool
+

Keep / reestablish the database connection if no queries +have been sent for a length of time exceeding the +server’s idle timeout.

+
+ +
+
+db_select([$database = ''])
+
+++ + + + + + + + +
Parameters:
    +
  • $database (string) – Database name
    • +
+
Returns:

TRUE on success, FALSE on failure

+
Return type:

bool

+
+

Select / switch the current database.

+
+ +
+
+db_set_charset($charset)
+
+++ + + + + + + + +
Parameters:
    +
  • $charset (string) – Character set name
    • +
+
Returns:

TRUE on success, FALSE on failure

+
Return type:

bool

+
+

Set client character set.

+
+ +
+
+platform()
+
+++ + + + + + +
Returns:Platform name
Return type:string
+

The name of the platform in use (mysql, mssql, etc…).

+
+ +
+
+version()
+
+++ + + + + + +
Returns:The version of the database being used
Return type:string
+

Database version number.

+
+ +
+
+query($sql[, $binds = FALSE[, $return_object = NULL]])
+
+++ + + + + + + + +
Parameters:
    +
  • $sql (string) – The SQL statement to execute
    • +
  • $binds (array) – An array of binding data
    • +
  • $return_object (bool) – Whether to return a result object or not
    • +
+
Returns:

TRUE for successful “write-type” queries, CI_DB_result instance (method chaining) on “query” success, FALSE on failure

+
Return type:

mixed

+
+

Execute an SQL query.

+

Accepts an SQL string as input and returns a result object +upon successful execution of a “read” type query.

+

Returns:

+
+
    +
  • Boolean TRUE upon successful execution of a “write type” queries
    • +
  • Boolean FALSE upon failure
    • +
  • CI_DB_result object for “read type” queries
    • +
+
+
+ +
+
+simple_query($sql)
+
+++ + + + + + + + +
Parameters:
    +
  • $sql (string) – The SQL statement to execute
    • +
+
Returns:

Whatever the underlying driver’s “query” function returns

+
Return type:

mixed

+
+

A simplified version of the query() method, appropriate +for use when you don’t need to get a result object or to +just send a query to the database and not care for the result.

+
+ +
+
+affected_rows()
+
+++ + + + + + +
Returns:Number of rows affected
Return type:int
+

Returns the number of rows changed by the last executed query.

+

Useful for checking how much rows were created, updated or deleted +during the last executed query.

+
+ +
+
+trans_strict([$mode = TRUE])
+
+++ + + + + + +
Parameters:
    +
  • $mode (bool) – Strict mode flag
    • +
+
Return type:

void

+
+

Enable/disable transaction “strict” mode.

+

When strict mode is enabled, if you are running multiple +groups of transactions and one group fails, all subsequent +groups will be rolled back.

+

If strict mode is disabled, each group is treated +autonomously, meaning a failure of one group will not +affect any others.

+
+ +
+
+trans_off()
+
+++ + + + +
Return type:void
+

Disables transactions at run-time.

+
+ +
+
+trans_start([$test_mode = FALSE])
+
+++ + + + + + + + +
Parameters:
    +
  • $test_mode (bool) – Test mode flag
    • +
+
Returns:

TRUE on success, FALSE on failure

+
Return type:

bool

+
+

Start a transaction.

+
+ +
+
+trans_complete()
+
+++ + + + + + +
Returns:TRUE on success, FALSE on failure
Return type:bool
+

Complete Transaction.

+
+ +
+
+trans_status()
+
+++ + + + + + +
Returns:TRUE if the transaction succeeded, FALSE if it failed
Return type:bool
+

Lets you retrieve the transaction status flag to +determine if it has failed.

+
+ +
+
+compile_binds($sql, $binds)
+
+++ + + + + + + + +
Parameters:
    +
  • $sql (string) – The SQL statement
    • +
  • $binds (array) – An array of binding data
    • +
+
Returns:

The updated SQL statement

+
Return type:

string

+
+

Compiles an SQL query with the bind values passed for it.

+
+ +
+
+is_write_type($sql)
+
+++ + + + + + + + +
Parameters:
    +
  • $sql (string) – The SQL statement
    • +
+
Returns:

TRUE if the SQL statement is of “write type”, FALSE if not

+
Return type:

bool

+
+

Determines if a query is of a “write” type (such as +INSERT, UPDATE, DELETE) or “read” type (i.e. SELECT).

+
+ +
+
+elapsed_time([$decimals = 6])
+
+++ + + + + + + + +
Parameters:
    +
  • $decimals (int) – The number of decimal places
    • +
+
Returns:

The aggregate query elapsed time, in microseconds

+
Return type:

string

+
+

Calculate the aggregate query elapsed time.

+
+ +
+
+total_queries()
+
+++ + + + + + +
Returns:The total number of queries executed
Return type:int
+

Returns the total number of queries that have been +executed so far.

+
+ +
+
+last_query()
+
+++ + + + + + +
Returns:The last query executed
Return type:string
+

Returns the last query that was executed.

+
+ +
+
+escape($str)
+
+++ + + + + + + + +
Parameters:
    +
  • $str (mixed) – The value to escape, or an array of multiple ones
    • +
+
Returns:

The escaped value(s)

+
Return type:

mixed

+
+

Escapes input data based on type, including boolean and +NULLs.

+
+ +
+
+escape_str($str[, $like = FALSE])
+
+++ + + + + + + + +
Parameters:
    +
  • $str (mixed) – A string value or array of multiple ones
    • +
  • $like (bool) – Whether or not the string will be used in a LIKE condition
    • +
+
Returns:

The escaped string(s)

+
Return type:

mixed

+
+

Escapes string values.

+
+

Warning

+

The returned strings do NOT include quotes +around them.

+
+
+ +
+
+escape_like_str($str)
+
+++ + + + + + + + +
Parameters:
    +
  • $str (mixed) – A string value or array of multiple ones
    • +
+
Returns:

The escaped string(s)

+
Return type:

mixed

+
+

Escape LIKE strings.

+

Similar to escape_str(), but will also escape the % +and _ wildcard characters, so that they don’t cause +false-positives in LIKE conditions.

+
+

Important

+

The escape_like_str() method uses ‘!’ (exclamation mark) +to escape special characters for LIKE conditions. Because this +method escapes partial strings that you would wrap in quotes +yourself, it cannot automatically add the ESCAPE '!' +condition for you, and so you’ll have to manually do that.

+
+
+ +
+
+primary($table)
+
+++ + + + + + + + +
Parameters:
    +
  • $table (string) – Table name
    • +
+
Returns:

The primary key name, FALSE if none

+
Return type:

string

+
+

Retrieves the primary key of a table.

+
+

Note

+

If the database platform does not support primary +key detection, the first column name may be assumed +as the primary key.

+
+
+ +
+
+count_all([$table = ''])
+
+++ + + + + + + + +
Parameters:
    +
  • $table (string) – Table name
    • +
+
Returns:

Row count for the specified table

+
Return type:

int

+
+

Returns the total number of rows in a table, or 0 if no +table was provided.

+
+ +
+
+list_tables([$constrain_by_prefix = FALSE])
+
+++ + + + + + + + +
Parameters:
    +
  • $constrain_by_prefix (bool) – TRUE to match table names by the configured dbprefix
    • +
+
Returns:

Array of table names or FALSE on failure

+
Return type:

array

+
+

Gets a list of the tables in the current database.

+
+ +
+
+table_exists($table_name)
+
+++ + + + + + + + +
Parameters:
    +
  • $table_name (string) – The table name
    • +
+
Returns:

TRUE if that table exists, FALSE if not

+
Return type:

bool

+
+

Determine if a particular table exists.

+
+ +
+
+list_fields($table)
+
+++ + + + + + + + +
Parameters:
    +
  • $table (string) – The table name
    • +
+
Returns:

Array of field names or FALSE on failure

+
Return type:

array

+
+

Gets a list of the field names in a table.

+
+ +
+
+field_exists($field_name, $table_name)
+
+++ + + + + + + + +
Parameters:
    +
  • $table_name (string) – The table name
    • +
  • $field_name (string) – The field name
    • +
+
Returns:

TRUE if that field exists in that table, FALSE if not

+
Return type:

bool

+
+

Determine if a particular field exists.

+
+ +
+
+field_data($table)
+
+++ + + + + + + + +
Parameters:
    +
  • $table (string) – The table name
    • +
+
Returns:

Array of field data items or FALSE on failure

+
Return type:

array

+
+

Gets a list containing field data about a table.

+
+ +
+
+escape_identifiers($item)
+
+++ + + + + + + + +
Parameters:
    +
  • $item (mixed) – The item or array of items to escape
    • +
+
Returns:

The input item(s), escaped

+
Return type:

mixed

+
+

Escape SQL identifiers, such as column, table and names.

+
+ +
+
+insert_string($table, $data)
+
+++ + + + + + + + +
Parameters:
    +
  • $table (string) – The target table
    • +
  • $data (array) – An associative array of key/value pairs
    • +
+
Returns:

The SQL INSERT statement, as a string

+
Return type:

string

+
+

Generate an INSERT statement string.

+
+ +
+
+update_string($table, $data, $where)
+
+++ + + + + + + + +
Parameters:
    +
  • $table (string) – The target table
    • +
  • $data (array) – An associative array of key/value pairs
    • +
  • $where (mixed) – The WHERE statement conditions
    • +
+
Returns:

The SQL UPDATE statement, as a string

+
Return type:

string

+
+

Generate an UPDATE statement string.

+
+ +
+
+call_function($function)
+
+++ + + + + + + + +
Parameters:
    +
  • $function (string) – Function name
    • +
+
Returns:

The function result

+
Return type:

string

+
+

Runs a native PHP function , using a platform agnostic +wrapper.

+
+ +
+
+cache_set_path([$path = ''])
+
+++ + + + + + +
Parameters:
    +
  • $path (string) – Path to the cache directory
    • +
+
Return type:

void

+
+

Sets the directory path to use for caching storage.

+
+ +
+
+cache_on()
+
+++ + + + + + +
Returns:TRUE if caching is on, FALSE if not
Return type:bool
+

Enable database results caching.

+
+ +
+
+cache_off()
+
+++ + + + + + +
Returns:TRUE if caching is on, FALSE if not
Return type:bool
+

Disable database results caching.

+
+ +
+
+cache_delete([$segment_one = ''[, $segment_two = '']])
+
+++ + + + + + + + +
Parameters:
    +
  • $segment_one (string) – First URI segment
    • +
  • $segment_two (string) – Second URI segment
    • +
+
Returns:

TRUE on success, FALSE on failure

+
Return type:

bool

+
+

Delete the cache files associated with a particular URI.

+
+ +
+
+cache_delete_all()
+
+++ + + + + + +
Returns:TRUE on success, FALSE on failure
Return type:bool
+

Delete all cache files.

+
+ +
+
+close()
+
+++ + + + +
Return type:void
+

Close the DB Connection.

+
+ +
+
+display_error([$error = ''[, $swap = ''[, $native = FALSE]]])
+
+++ + + + + + + + + + +
Parameters:
    +
  • $error (string) – The error message
    • +
  • $swap (string) – Any “swap” values
    • +
  • $native (bool) – Whether to localize the message
    • +
+
Return type:

void

+
Returns:

Displays the DB error screensends the application/views/errors/error_db.php template

+
Return type:

string

+
+

Display an error message and stop script execution.

+

The message is displayed using the +application/views/errors/error_db.php template.

+
+ +
+
+protect_identifiers($item[, $prefix_single = FALSE[, $protect_identifiers = NULL[, $field_exists = TRUE]]])
+
+++ + + + + + + + +
Parameters:
    +
  • $item (string) – The item to work with
    • +
  • $prefix_single (bool) – Whether to apply the dbprefix even if the input item is a single identifier
    • +
  • $protect_identifiers (bool) – Whether to quote identifiers
    • +
  • $field_exists (bool) – Whether the supplied item contains a field name or not
    • +
+
Returns:

The modified item

+
Return type:

string

+
+

Takes a column or table name (optionally with an alias) +and applies the configured dbprefix to it.

+

Some logic is necessary in order to deal with +column names that include the path.

+

Consider a query like this:

+
SELECT * FROM hostname.database.table.column AS c FROM hostname.database.table
+
+
+

Or a query with aliasing:

+
SELECT m.member_id, m.member_name FROM members AS m
+
+
+

Since the column name can include up to four segments +(host, DB, table, column) or also have an alias prefix, +we need to do a bit of work to figure this out and +insert the table prefix (if it exists) in the proper +position, and escape only the correct identifiers.

+

This method is used extensively by the Query Builder class.

+
+ +
+ +
+ + +
+
+ + + + +
+ +
+

+ © Copyright 2014 - 2018, British Columbia Institute of Technology. + Last updated on Mar 22, 2018. +

+
+ + Built with Sphinx using a theme provided by Read the Docs. + +
+
+
+ +
+ +
+ + + + + + + + + + + + + + + + + + + + + + + + \ No newline at end of file diff --git a/user_guide/database/examples.html b/user_guide/database/examples.html new file mode 100644 index 000000000..70c762329 --- /dev/null +++ b/user_guide/database/examples.html @@ -0,0 +1,597 @@ + + + + + + + + + + Database Quick Start: Example Code — CodeIgniter 3.1.8 documentation + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +
+ + + + +
+ + + + + + +
+
+
+ +
+
+
+ +
+

Database Quick Start: Example Code

+

The following page contains example code showing how the database class +is used. For complete details please read the individual pages +describing each function.

+
+

Initializing the Database Class

+

The following code loads and initializes the database class based on +your configuration settings:

+
$this->load->database();
+
+
+

Once loaded the class is ready to be used as described below.

+

Note: If all your pages require database access you can connect +automatically. See the connecting page for details.

+
+
+

Standard Query With Multiple Results (Object Version)

+
$query = $this->db->query('SELECT name, title, email FROM my_table');
+
+foreach ($query->result() as $row)
+{
+        echo $row->title;
+        echo $row->name;
+        echo $row->email;
+}
+
+echo 'Total Results: ' . $query->num_rows();
+
+
+

The above result() function returns an array of objects. Example: +$row->title

+
+
+

Standard Query With Multiple Results (Array Version)

+
$query = $this->db->query('SELECT name, title, email FROM my_table');
+
+foreach ($query->result_array() as $row)
+{
+        echo $row['title'];
+        echo $row['name'];
+        echo $row['email'];
+}
+
+
+

The above result_array() function returns an array of standard array +indexes. Example: $row[‘title’]

+
+
+

Standard Query With Single Result

+
$query = $this->db->query('SELECT name FROM my_table LIMIT 1');
+$row = $query->row();
+echo $row->name;
+
+
+

The above row() function returns an object. Example: $row->name

+
+
+

Standard Query With Single Result (Array version)

+
$query = $this->db->query('SELECT name FROM my_table LIMIT 1');
+$row = $query->row_array();
+echo $row['name'];
+
+
+

The above row_array() function returns an array. Example: +$row[‘name’]

+
+
+

Standard Insert

+
$sql = "INSERT INTO mytable (title, name) VALUES (".$this->db->escape($title).", ".$this->db->escape($name).")";
+$this->db->query($sql);
+echo $this->db->affected_rows();
+
+
+
+
+

Query Builder Query

+

The Query Builder Pattern gives you a simplified +means of retrieving data:

+
$query = $this->db->get('table_name');
+
+foreach ($query->result() as $row)
+{
+        echo $row->title;
+}
+
+
+

The above get() function retrieves all the results from the supplied +table. The Query Builder class contains a full +compliment of functions for working with data.

+
+
+

Query Builder Insert

+
$data = array(
+        'title' => $title,
+        'name' => $name,
+        'date' => $date
+);
+
+$this->db->insert('mytable', $data);  // Produces: INSERT INTO mytable (title, name, date) VALUES ('{$title}', '{$name}', '{$date}')
+
+
+
+
+ + +
+
+ + + + +
+ +
+

+ © Copyright 2014 - 2018, British Columbia Institute of Technology. + Last updated on Mar 22, 2018. +

+
+ + Built with Sphinx using a theme provided by Read the Docs. + +
+
+
+ +
+ +
+ + + + + + + + + + + + + + + + + + + + + + + + \ No newline at end of file diff --git a/user_guide/database/forge.html b/user_guide/database/forge.html new file mode 100644 index 000000000..5d5651620 --- /dev/null +++ b/user_guide/database/forge.html @@ -0,0 +1,1034 @@ + + + + + + + + + + Database Forge Class — CodeIgniter 3.1.8 documentation + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +
+ + + + +
+ + + + + + +
+
+
+ +
+
+
+ +
+

Database Forge Class

+

The Database Forge Class contains methods that help you manage your +database.

+ +
+

Initializing the Forge Class

+
+

Important

+

In order to initialize the Forge class, your database +driver must already be running, since the forge class relies on it.

+
+

Load the Forge Class as follows:

+
$this->load->dbforge()
+
+
+

You can also pass another database object to the DB Forge loader, in case +the database you want to manage isn’t the default one:

+
$this->myforge = $this->load->dbforge($this->other_db, TRUE);
+
+
+

In the above example, we’re passing a custom database object as the first +parameter and then tell it to return the dbforge object, instead of +assigning it directly to $this->dbforge.

+
+

Note

+

Both of the parameters can be used individually, just pass an empty +value as the first one if you wish to skip it.

+
+

Once initialized you will access the methods using the $this->dbforge +object:

+
$this->dbforge->some_method();
+
+
+
+
+

Creating and Dropping Databases

+

$this->dbforge->create_database(‘db_name’)

+

Permits you to create the database specified in the first parameter. +Returns TRUE/FALSE based on success or failure:

+
if ($this->dbforge->create_database('my_db'))
+{
+        echo 'Database created!';
+}
+
+
+

$this->dbforge->drop_database(‘db_name’)

+

Permits you to drop the database specified in the first parameter. +Returns TRUE/FALSE based on success or failure:

+
if ($this->dbforge->drop_database('my_db'))
+{
+        echo 'Database deleted!';
+}
+
+
+
+
+

Creating and Dropping Tables

+

There are several things you may wish to do when creating tables. Add +fields, add keys to the table, alter columns. CodeIgniter provides a +mechanism for this.

+
+

Adding fields

+

Fields are created via an associative array. Within the array you must +include a ‘type’ key that relates to the datatype of the field. For +example, INT, VARCHAR, TEXT, etc. Many datatypes (for example VARCHAR) +also require a ‘constraint’ key.

+
$fields = array(
+        'users' => array(
+                'type' => 'VARCHAR',
+                'constraint' => '100',
+        ),
+);
+// will translate to "users VARCHAR(100)" when the field is added.
+
+
+

Additionally, the following key/values can be used:

+
    +
  • unsigned/true : to generate “UNSIGNED” in the field definition.
    • +
  • default/value : to generate a default value in the field definition.
    • +
  • null/true : to generate “NULL” in the field definition. Without this, +the field will default to “NOT NULL”.
    • +
  • auto_increment/true : generates an auto_increment flag on the +field. Note that the field type must be a type that supports this, +such as integer.
    • +
  • unique/true : to generate a unique key for the field definition.
    • +
+
$fields = array(
+        'blog_id' => array(
+                'type' => 'INT',
+                'constraint' => 5,
+                'unsigned' => TRUE,
+                'auto_increment' => TRUE
+        ),
+        'blog_title' => array(
+                'type' => 'VARCHAR',
+                'constraint' => '100',
+                'unique' => TRUE,
+        ),
+        'blog_author' => array(
+                'type' =>'VARCHAR',
+                'constraint' => '100',
+                'default' => 'King of Town',
+        ),
+        'blog_description' => array(
+                'type' => 'TEXT',
+                'null' => TRUE,
+        ),
+);
+
+
+

After the fields have been defined, they can be added using +$this->dbforge->add_field($fields); followed by a call to the +create_table() method.

+

$this->dbforge->add_field()

+

The add fields method will accept the above array.

+
+

Passing strings as fields

+

If you know exactly how you want a field to be created, you can pass the +string into the field definitions with add_field()

+
$this->dbforge->add_field("label varchar(100) NOT NULL DEFAULT 'default label'");
+
+
+
+

Note

+

Passing raw strings as fields cannot be followed by add_key() calls on those fields.

+
+
+

Note

+

Multiple calls to add_field() are cumulative.

+
+
+
+

Creating an id field

+

There is a special exception for creating id fields. A field with type +id will automatically be assigned as an INT(9) auto_incrementing +Primary Key.

+
$this->dbforge->add_field('id');
+// gives id INT(9) NOT NULL AUTO_INCREMENT
+
+
+
+
+
+

Adding Keys

+

Generally speaking, you’ll want your table to have Keys. This is +accomplished with $this->dbforge->add_key(‘field’). An optional second +parameter set to TRUE will make it a primary key. Note that add_key() +must be followed by a call to create_table().

+

Multiple column non-primary keys must be sent as an array. Sample output +below is for MySQL.

+
$this->dbforge->add_key('blog_id', TRUE);
+// gives PRIMARY KEY `blog_id` (`blog_id`)
+
+$this->dbforge->add_key('blog_id', TRUE);
+$this->dbforge->add_key('site_id', TRUE);
+// gives PRIMARY KEY `blog_id_site_id` (`blog_id`, `site_id`)
+
+$this->dbforge->add_key('blog_name');
+// gives KEY `blog_name` (`blog_name`)
+
+$this->dbforge->add_key(array('blog_name', 'blog_label'));
+// gives KEY `blog_name_blog_label` (`blog_name`, `blog_label`)
+
+
+
+
+

Creating a table

+

After fields and keys have been declared, you can create a new table +with

+
$this->dbforge->create_table('table_name');
+// gives CREATE TABLE table_name
+
+
+

An optional second parameter set to TRUE adds an “IF NOT EXISTS” clause +into the definition

+
$this->dbforge->create_table('table_name', TRUE);
+// gives CREATE TABLE IF NOT EXISTS table_name
+
+
+

You could also pass optional table attributes, such as MySQL’s ENGINE:

+
$attributes = array('ENGINE' => 'InnoDB');
+$this->dbforge->create_table('table_name', FALSE, $attributes);
+// produces: CREATE TABLE `table_name` (...) ENGINE = InnoDB DEFAULT CHARACTER SET utf8 COLLATE utf8_general_ci
+
+
+
+

Note

+

Unless you specify the CHARACTER SET and/or COLLATE attributes, +create_table() will always add them with your configured char_set +and dbcollat values, as long as they are not empty (MySQL only).

+
+
+
+

Dropping a table

+

Execute a DROP TABLE statement and optionally add an IF EXISTS clause.

+
// Produces: DROP TABLE table_name
+$this->dbforge->drop_table('table_name');
+
+// Produces: DROP TABLE IF EXISTS table_name
+$this->dbforge->drop_table('table_name',TRUE);
+
+
+
+
+

Renaming a table

+

Executes a TABLE rename

+
$this->dbforge->rename_table('old_table_name', 'new_table_name');
+// gives ALTER TABLE old_table_name RENAME TO new_table_name
+
+
+
+
+
+

Modifying Tables

+
+

Adding a Column to a Table

+

$this->dbforge->add_column()

+

The add_column() method is used to modify an existing table. It +accepts the same field array as above, and can be used for an unlimited +number of additional fields.

+
$fields = array(
+        'preferences' => array('type' => 'TEXT')
+);
+$this->dbforge->add_column('table_name', $fields);
+// Executes: ALTER TABLE table_name ADD preferences TEXT
+
+
+

If you are using MySQL or CUBIRD, then you can take advantage of their +AFTER and FIRST clauses to position the new column.

+

Examples:

+
// Will place the new column after the `another_field` column:
+$fields = array(
+        'preferences' => array('type' => 'TEXT', 'after' => 'another_field')
+);
+
+// Will place the new column at the start of the table definition:
+$fields = array(
+        'preferences' => array('type' => 'TEXT', 'first' => TRUE)
+);
+
+
+
+
+

Dropping a Column From a Table

+

$this->dbforge->drop_column()

+

Used to remove a column from a table.

+
$this->dbforge->drop_column('table_name', 'column_to_drop');
+
+
+
+
+

Modifying a Column in a Table

+

$this->dbforge->modify_column()

+

The usage of this method is identical to add_column(), except it +alters an existing column rather than adding a new one. In order to +change the name you can add a “name” key into the field defining array.

+
$fields = array(
+        'old_name' => array(
+                'name' => 'new_name',
+                'type' => 'TEXT',
+        ),
+);
+$this->dbforge->modify_column('table_name', $fields);
+// gives ALTER TABLE table_name CHANGE old_name new_name TEXT
+
+
+
+
+
+

Class Reference

+
+
+class CI_DB_forge
+
+
+add_column($table[, $field = array()[, $_after = NULL]])
+
+++ + + + + + + + +
Parameters:
    +
  • $table (string) – Table name to add the column to
    • +
  • $field (array) – Column definition(s)
    • +
  • $_after (string) – Column for AFTER clause (deprecated)
    • +
+
Returns:

TRUE on success, FALSE on failure

+
Return type:

bool

+
+

Adds a column to a table. Usage: See Adding a Column to a Table.

+
+ +
+
+add_field($field)
+
+++ + + + + + + + +
Parameters:
    +
  • $field (array) – Field definition to add
    • +
+
Returns:

CI_DB_forge instance (method chaining)

+
Return type:

CI_DB_forge

+
+

Adds a field to the set that will be used to create a table. Usage: See Adding fields.

+
+ +
+
+add_key($key[, $primary = FALSE])
+
+++ + + + + + + + +
Parameters:
    +
  • $key (array) – Name of a key field
    • +
  • $primary (bool) – Set to TRUE if it should be a primary key or a regular one
    • +
+
Returns:

CI_DB_forge instance (method chaining)

+
Return type:

CI_DB_forge

+
+

Adds a key to the set that will be used to create a table. Usage: See Adding Keys.

+
+ +
+
+create_database($db_name)
+
+++ + + + + + + + +
Parameters:
    +
  • $db_name (string) – Name of the database to create
    • +
+
Returns:

TRUE on success, FALSE on failure

+
Return type:

bool

+
+

Creates a new database. Usage: See Creating and Dropping Databases.

+
+ +
+
+create_table($table[, $if_not_exists = FALSE[, array $attributes = array()]])
+
+++ + + + + + + + +
Parameters:
    +
  • $table (string) – Name of the table to create
    • +
  • $if_not_exists (string) – Set to TRUE to add an ‘IF NOT EXISTS’ clause
    • +
  • $attributes (string) – An associative array of table attributes
    • +
+
Returns:

TRUE on success, FALSE on failure

+
Return type:

bool

+
+

Creates a new table. Usage: See Creating a table.

+
+ +
+
+drop_column($table, $column_name)
+
+++ + + + + + + + +
Parameters:
    +
  • $table (string) – Table name
    • +
  • $column_name (array) – The column name to drop
    • +
+
Returns:

TRUE on success, FALSE on failure

+
Return type:

bool

+
+

Drops a column from a table. Usage: See Dropping a Column From a Table.

+
+ +
+
+drop_database($db_name)
+
+++ + + + + + + + +
Parameters:
    +
  • $db_name (string) – Name of the database to drop
    • +
+
Returns:

TRUE on success, FALSE on failure

+
Return type:

bool

+
+

Drops a database. Usage: See Creating and Dropping Databases.

+
+ +
+
+drop_table($table_name[, $if_exists = FALSE])
+
+++ + + + + + + + +
Parameters:
    +
  • $table (string) – Name of the table to drop
    • +
  • $if_exists (string) – Set to TRUE to add an ‘IF EXISTS’ clause
    • +
+
Returns:

TRUE on success, FALSE on failure

+
Return type:

bool

+
+

Drops a table. Usage: See Dropping a table.

+
+ +
+
+modify_column($table, $field)
+
+++ + + + + + + + +
Parameters:
    +
  • $table (string) – Table name
    • +
  • $field (array) – Column definition(s)
    • +
+
Returns:

TRUE on success, FALSE on failure

+
Return type:

bool

+
+

Modifies a table column. Usage: See Modifying a Column in a Table.

+
+ +
+
+rename_table($table_name, $new_table_name)
+
+++ + + + + + + + +
Parameters:
    +
  • $table (string) – Current of the table
    • +
  • $new_table_name (string) – New name of the table
    • +
+
Returns:

TRUE on success, FALSE on failure

+
Return type:

bool

+
+

Renames a table. Usage: See Renaming a table.

+
+ +
+ +
+
+ + +
+
+ + + + +
+ +
+

+ © Copyright 2014 - 2018, British Columbia Institute of Technology. + Last updated on Mar 22, 2018. +

+
+ + Built with Sphinx using a theme provided by Read the Docs. + +
+
+
+ +
+ +
+ + + + + + + + + + + + + + + + + + + + + + + + \ No newline at end of file diff --git a/user_guide/database/helpers.html b/user_guide/database/helpers.html new file mode 100644 index 000000000..0f82b5593 --- /dev/null +++ b/user_guide/database/helpers.html @@ -0,0 +1,592 @@ + + + + + + + + + + Query Helper Methods — CodeIgniter 3.1.8 documentation + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +
+ + + + +
+ + + + + + +
+
+
+ +
+
+
+ +
+

Query Helper Methods

+
+

Information From Executing a Query

+

$this->db->insert_id()

+

The insert ID number when performing database inserts.

+
+

Note

+

If using the PDO driver with PostgreSQL, or using the Interbase +driver, this function requires a $name parameter, which specifies the +appropriate sequence to check for the insert id.

+
+

$this->db->affected_rows()

+

Displays the number of affected rows, when doing “write” type queries +(insert, update, etc.).

+
+

Note

+

In MySQL “DELETE FROM TABLE” returns 0 affected rows. The database +class has a small hack that allows it to return the correct number of +affected rows. By default this hack is enabled but it can be turned off +in the database driver file.

+
+

$this->db->last_query()

+

Returns the last query that was run (the query string, not the result). +Example:

+
$str = $this->db->last_query();
+
+// Produces:  SELECT * FROM sometable....
+
+
+
+

Note

+

Disabling the save_queries setting in your database +configuration will render this function useless.

+
+
+
+

Information About Your Database

+

$this->db->count_all()

+

Permits you to determine the number of rows in a particular table. +Submit the table name in the first parameter. Example:

+
echo $this->db->count_all('my_table');
+
+// Produces an integer, like 25
+
+
+

$this->db->platform()

+

Outputs the database platform you are running (MySQL, MS SQL, Postgres, +etc…):

+
echo $this->db->platform();
+
+
+

$this->db->version()

+

Outputs the database version you are running:

+
echo $this->db->version();
+
+
+
+
+

Making Your Queries Easier

+

$this->db->insert_string()

+

This function simplifies the process of writing database inserts. It +returns a correctly formatted SQL insert string. Example:

+
$data = array('name' => $name, 'email' => $email, 'url' => $url);
+
+$str = $this->db->insert_string('table_name', $data);
+
+
+

The first parameter is the table name, the second is an associative +array with the data to be inserted. The above example produces:

+
INSERT INTO table_name (name, email, url) VALUES ('Rick', 'rick@example.com', 'example.com')
+
+
+
+

Note

+

Values are automatically escaped, producing safer queries.

+
+

$this->db->update_string()

+

This function simplifies the process of writing database updates. It +returns a correctly formatted SQL update string. Example:

+
$data = array('name' => $name, 'email' => $email, 'url' => $url);
+
+$where = "author_id = 1 AND status = 'active'";
+
+$str = $this->db->update_string('table_name', $data, $where);
+
+
+

The first parameter is the table name, the second is an associative +array with the data to be updated, and the third parameter is the +“where” clause. The above example produces:

+
UPDATE table_name SET name = 'Rick', email = 'rick@example.com', url = 'example.com' WHERE author_id = 1 AND status = 'active'
+
+
+
+

Note

+

Values are automatically escaped, producing safer queries.

+
+
+
+ + +
+
+ + + + +
+ +
+

+ © Copyright 2014 - 2018, British Columbia Institute of Technology. + Last updated on Mar 22, 2018. +

+
+ + Built with Sphinx using a theme provided by Read the Docs. + +
+
+
+ +
+ +
+ + + + + + + + + + + + + + + + + + + + + + + + \ No newline at end of file diff --git a/user_guide/database/index.html b/user_guide/database/index.html new file mode 100644 index 000000000..94a8e026f --- /dev/null +++ b/user_guide/database/index.html @@ -0,0 +1,514 @@ + + + + + + + + + + Database Reference — CodeIgniter 3.1.8 documentation + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +
+ + + + +
+ + + + + + +
+
+
+
    +
  • Docs »
    • + +
  • Database Reference
    • +
  • + +
    • +
    + classic layout +
    +
+
+
+
+ +
+

Database Reference

+

CodeIgniter comes with a full-featured and very fast abstracted database +class that supports both traditional structures and Query Builder +patterns. The database functions offer clear, simple syntax.

+
+ +
+
+ + +
+
+ + + + +
+ +
+

+ © Copyright 2014 - 2018, British Columbia Institute of Technology. + Last updated on Mar 22, 2018. +

+
+ + Built with Sphinx using a theme provided by Read the Docs. + +
+
+
+ +
+ +
+ + + + + + + + + + + + + + + + + + + + + + + + \ No newline at end of file diff --git a/user_guide/database/metadata.html b/user_guide/database/metadata.html new file mode 100644 index 000000000..34ce935e3 --- /dev/null +++ b/user_guide/database/metadata.html @@ -0,0 +1,614 @@ + + + + + + + + + + Database Metadata — CodeIgniter 3.1.8 documentation + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +
+ + + + +
+ + + + + + +
+
+
+ +
+
+
+ +
+

Database Metadata

+
+

Table MetaData

+

These functions let you fetch table information.

+
+

List the Tables in Your Database

+

$this->db->list_tables();

+

Returns an array containing the names of all the tables in the database +you are currently connected to. Example:

+
$tables = $this->db->list_tables();
+
+foreach ($tables as $table)
+{
+        echo $table;
+}
+
+
+
+
+

Determine If a Table Exists

+

$this->db->table_exists();

+

Sometimes it’s helpful to know whether a particular table exists before +running an operation on it. Returns a boolean TRUE/FALSE. Usage example:

+
if ($this->db->table_exists('table_name'))
+{
+        // some code...
+}
+
+
+
+

Note

+

Replace table_name with the name of the table you are looking for.

+
+
+
+
+

Field MetaData

+
+

List the Fields in a Table

+

$this->db->list_fields()

+

Returns an array containing the field names. This query can be called +two ways:

+

1. You can supply the table name and call it from the $this->db-> +object:

+
$fields = $this->db->list_fields('table_name');
+
+foreach ($fields as $field)
+{
+        echo $field;
+}
+
+
+

2. You can gather the field names associated with any query you run by +calling the function from your query result object:

+
$query = $this->db->query('SELECT * FROM some_table');
+
+foreach ($query->list_fields() as $field)
+{
+        echo $field;
+}
+
+
+
+
+

Determine If a Field is Present in a Table

+

$this->db->field_exists()

+

Sometimes it’s helpful to know whether a particular field exists before +performing an action. Returns a boolean TRUE/FALSE. Usage example:

+
if ($this->db->field_exists('field_name', 'table_name'))
+{
+        // some code...
+}
+
+
+
+

Note

+

Replace field_name with the name of the column you are looking +for, and replace table_name with the name of the table you are +looking for.

+
+
+
+

Retrieve Field Metadata

+

$this->db->field_data()

+

Returns an array of objects containing field information.

+

Sometimes it’s helpful to gather the field names or other metadata, like +the column type, max length, etc.

+
+

Note

+

Not all databases provide meta-data.

+
+

Usage example:

+
$fields = $this->db->field_data('table_name');
+
+foreach ($fields as $field)
+{
+        echo $field->name;
+        echo $field->type;
+        echo $field->max_length;
+        echo $field->primary_key;
+}
+
+
+

If you have run a query already you can use the result object instead of +supplying the table name:

+
$query = $this->db->query("YOUR QUERY");
+$fields = $query->field_data();
+
+
+

The following data is available from this function if supported by your +database:

+
    +
  • name - column name
    • +
  • max_length - maximum length of the column
    • +
  • primary_key - 1 if the column is a primary key
    • +
  • type - the type of the column
    • +
+
+
+
+ + +
+
+ + + + +
+ +
+

+ © Copyright 2014 - 2018, British Columbia Institute of Technology. + Last updated on Mar 22, 2018. +

+
+ + Built with Sphinx using a theme provided by Read the Docs. + +
+
+
+ +
+ +
+ + + + + + + + + + + + + + + + + + + + + + + + \ No newline at end of file diff --git a/user_guide/database/queries.html b/user_guide/database/queries.html new file mode 100644 index 000000000..73e642979 --- /dev/null +++ b/user_guide/database/queries.html @@ -0,0 +1,658 @@ + + + + + + + + + + Queries — CodeIgniter 3.1.8 documentation + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +
+ + + + +
+ + + + + + +
+
+
+ +
+
+
+ +
+

Queries

+
+

Query Basics

+
+

Regular Queries

+

To submit a query, use the query function:

+
$this->db->query('YOUR QUERY HERE');
+
+
+

The query() function returns a database result object when “read” +type queries are run, which you can use to show your +results. When “write” type queries are run it simply +returns TRUE or FALSE depending on success or failure. When retrieving +data you will typically assign the query to your own variable, like +this:

+
$query = $this->db->query('YOUR QUERY HERE');
+
+
+
+
+

Simplified Queries

+

The simple_query method is a simplified version of the +$this->db->query() method. It DOES +NOT return a database result set, nor does it set the query timer, or +compile bind data, or store your query for debugging. It simply lets you +submit a query. Most users will rarely use this function.

+

It returns whatever the database drivers’ “execute” function returns. +That typically is TRUE/FALSE on success or failure for write type queries +such as INSERT, DELETE or UPDATE statements (which is what it really +should be used for) and a resource/object on success for queries with +fetchable results.

+
if ($this->db->simple_query('YOUR QUERY'))
+{
+        echo "Success!";
+}
+else
+{
+        echo "Query failed!";
+}
+
+
+
+

Note

+

PostgreSQL’s pg_exec() function (for example) always +returns a resource on success, even for write type queries. +So take that in mind if you’re looking for a boolean value.

+
+
+
+
+

Working with Database prefixes manually

+

If you have configured a database prefix and would like to prepend it to +a table name for use in a native SQL query for example, then you can use +the following:

+
$this->db->dbprefix('tablename'); // outputs prefix_tablename
+
+
+

If for any reason you would like to change the prefix programatically +without needing to create a new connection, you can use this method:

+
$this->db->set_dbprefix('newprefix_');
+$this->db->dbprefix('tablename'); // outputs newprefix_tablename
+
+
+
+
+

Protecting identifiers

+

In many databases it is advisable to protect table and field names - for +example with backticks in MySQL. Query Builder queries are +automatically protected, however if you need to manually protect an +identifier you can use:

+
$this->db->protect_identifiers('table_name');
+
+
+
+

Important

+

Although the Query Builder will try its best to properly +quote any field and table names that you feed it, note that it +is NOT designed to work with arbitrary user input. DO NOT feed it +with unsanitized user data.

+
+

This function will also add a table prefix to your table, assuming you +have a prefix specified in your database config file. To enable the +prefixing set TRUE (boolean) via the second parameter:

+
$this->db->protect_identifiers('table_name', TRUE);
+
+
+
+
+

Escaping Queries

+

It’s a very good security practice to escape your data before submitting +it into your database. CodeIgniter has three methods that help you do +this:

+
    +

  1. $this->db->escape() This function determines the data type so +that it can escape only string data. It also automatically adds +single quotes around the data so you don’t have to:

    +
    $sql = "INSERT INTO table (title) VALUES(".$this->db->escape($title).")";
+
    +
    +
    2. +

  2. $this->db->escape_str() This function escapes the data passed to +it, regardless of type. Most of the time you’ll use the above +function rather than this one. Use the function like this:

    +
    $sql = "INSERT INTO table (title) VALUES('".$this->db->escape_str($title)."')";
+
    +
    +
    3. +

  3. $this->db->escape_like_str() This method should be used when +strings are to be used in LIKE conditions so that LIKE wildcards +(‘%’, ‘_’) in the string are also properly escaped.

    +
    4. +
+
$search = '20% raise';
+$sql = "SELECT id FROM table WHERE column LIKE '%" .
+    $this->db->escape_like_str($search)."%' ESCAPE '!'";
+
+
+
+

Important

+

The escape_like_str() method uses ‘!’ (exclamation mark) +to escape special characters for LIKE conditions. Because this +method escapes partial strings that you would wrap in quotes +yourself, it cannot automatically add the ESCAPE '!' +condition for you, and so you’ll have to manually do that.

+
+
+
+

Query Bindings

+

Bindings enable you to simplify your query syntax by letting the system +put the queries together for you. Consider the following example:

+
$sql = "SELECT * FROM some_table WHERE id = ? AND status = ? AND author = ?";
+$this->db->query($sql, array(3, 'live', 'Rick'));
+
+
+

The question marks in the query are automatically replaced with the +values in the array in the second parameter of the query function.

+

Binding also work with arrays, which will be transformed to IN sets:

+
$sql = "SELECT * FROM some_table WHERE id IN ? AND status = ? AND author = ?";
+$this->db->query($sql, array(array(3, 6), 'live', 'Rick'));
+
+
+

The resulting query will be:

+
SELECT * FROM some_table WHERE id IN (3,6) AND status = 'live' AND author = 'Rick'
+
+
+

The secondary benefit of using binds is that the values are +automatically escaped, producing safer queries. You don’t have to +remember to manually escape data; the engine does it automatically for +you.

+
+
+

Handling Errors

+

$this->db->error();

+

If you need to get the last error that has occurred, the error() method +will return an array containing its code and message. Here’s a quick +example:

+
if ( ! $this->db->simple_query('SELECT `example_field` FROM `example_table`'))
+{
+        $error = $this->db->error(); // Has keys 'code' and 'message'
+}
+
+
+
+
+ + +
+
+ + + + +
+ +
+

+ © Copyright 2014 - 2018, British Columbia Institute of Technology. + Last updated on Mar 22, 2018. +

+
+ + Built with Sphinx using a theme provided by Read the Docs. + +
+
+
+ +
+ +
+ + + + + + + + + + + + + + + + + + + + + + + + \ No newline at end of file diff --git a/user_guide/database/query_builder.html b/user_guide/database/query_builder.html new file mode 100644 index 000000000..f54f929c0 --- /dev/null +++ b/user_guide/database/query_builder.html @@ -0,0 +1,2714 @@ + + + + + + + + + + Query Builder Class — CodeIgniter 3.1.8 documentation + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +
+ + + + +
+ + + + + + +
+
+
+ +
+
+
+ +
+

Query Builder Class

+

CodeIgniter gives you access to a Query Builder class. This pattern +allows information to be retrieved, inserted, and updated in your +database with minimal scripting. In some cases only one or two lines +of code are necessary to perform a database action. +CodeIgniter does not require that each database table be its own class +file. It instead provides a more simplified interface.

+

Beyond simplicity, a major benefit to using the Query Builder features +is that it allows you to create database independent applications, since +the query syntax is generated by each database adapter. It also allows +for safer queries, since the values are escaped automatically by the +system.

+
+

Note

+

If you intend to write your own queries you can disable this +class in your database config file, allowing the core database library +and adapter to utilize fewer resources.

+
+ +
+

Selecting Data

+

The following functions allow you to build SQL SELECT statements.

+

$this->db->get()

+

Runs the selection query and returns the result. Can be used by itself +to retrieve all records from a table:

+
$query = $this->db->get('mytable');  // Produces: SELECT * FROM mytable
+
+
+

The second and third parameters enable you to set a limit and offset +clause:

+
$query = $this->db->get('mytable', 10, 20);
+
+// Executes: SELECT * FROM mytable LIMIT 20, 10
+// (in MySQL. Other databases have slightly different syntax)
+
+
+

You’ll notice that the above function is assigned to a variable named +$query, which can be used to show the results:

+
$query = $this->db->get('mytable');
+
+foreach ($query->result() as $row)
+{
+        echo $row->title;
+}
+
+
+

Please visit the result functions page for a full +discussion regarding result generation.

+

$this->db->get_compiled_select()

+

Compiles the selection query just like $this->db->get() but does not run +the query. This method simply returns the SQL query as a string.

+

Example:

+
$sql = $this->db->get_compiled_select('mytable');
+echo $sql;
+
+// Prints string: SELECT * FROM mytable
+
+
+

The second parameter enables you to set whether or not the query builder query +will be reset (by default it will be reset, just like when using $this->db->get()):

+
echo $this->db->limit(10,20)->get_compiled_select('mytable', FALSE);
+
+// Prints string: SELECT * FROM mytable LIMIT 20, 10
+// (in MySQL. Other databases have slightly different syntax)
+
+echo $this->db->select('title, content, date')->get_compiled_select();
+
+// Prints string: SELECT title, content, date FROM mytable LIMIT 20, 10
+
+
+

The key thing to notice in the above example is that the second query did not +utilize $this->db->from() and did not pass a table name into the first +parameter. The reason for this outcome is because the query has not been +executed using $this->db->get() which resets values or reset directly +using $this->db->reset_query().

+

$this->db->get_where()

+

Identical to the above function except that it permits you to add a +“where” clause in the second parameter, instead of using the db->where() +function:

+
$query = $this->db->get_where('mytable', array('id' => $id), $limit, $offset);
+
+
+

Please read the about the where function below for more information.

+
+

Note

+

get_where() was formerly known as getwhere(), which has been removed

+
+

$this->db->select()

+

Permits you to write the SELECT portion of your query:

+
$this->db->select('title, content, date');
+$query = $this->db->get('mytable');
+
+// Executes: SELECT title, content, date FROM mytable
+
+
+
+

Note

+

If you are selecting all (*) from a table you do not need to +use this function. When omitted, CodeIgniter assumes that you wish +to select all fields and automatically adds ‘SELECT *’.

+
+

$this->db->select() accepts an optional second parameter. If you set it +to FALSE, CodeIgniter will not try to protect your field or table names. +This is useful if you need a compound select statement where automatic +escaping of fields may break them.

+
$this->db->select('(SELECT SUM(payments.amount) FROM payments WHERE payments.invoice_id=4) AS amount_paid', FALSE);
+$query = $this->db->get('mytable');
+
+
+

$this->db->select_max()

+

Writes a SELECT MAX(field) portion for your query. You can optionally +include a second parameter to rename the resulting field.

+
$this->db->select_max('age');
+$query = $this->db->get('members');  // Produces: SELECT MAX(age) as age FROM members
+
+$this->db->select_max('age', 'member_age');
+$query = $this->db->get('members'); // Produces: SELECT MAX(age) as member_age FROM members
+
+
+

$this->db->select_min()

+

Writes a “SELECT MIN(field)” portion for your query. As with +select_max(), You can optionally include a second parameter to rename +the resulting field.

+
$this->db->select_min('age');
+$query = $this->db->get('members'); // Produces: SELECT MIN(age) as age FROM members
+
+
+

$this->db->select_avg()

+

Writes a “SELECT AVG(field)” portion for your query. As with +select_max(), You can optionally include a second parameter to rename +the resulting field.

+
$this->db->select_avg('age');
+$query = $this->db->get('members'); // Produces: SELECT AVG(age) as age FROM members
+
+
+

$this->db->select_sum()

+

Writes a “SELECT SUM(field)” portion for your query. As with +select_max(), You can optionally include a second parameter to rename +the resulting field.

+
$this->db->select_sum('age');
+$query = $this->db->get('members'); // Produces: SELECT SUM(age) as age FROM members
+
+
+

$this->db->from()

+

Permits you to write the FROM portion of your query:

+
$this->db->select('title, content, date');
+$this->db->from('mytable');
+$query = $this->db->get();  // Produces: SELECT title, content, date FROM mytable
+
+
+
+

Note

+

As shown earlier, the FROM portion of your query can be specified +in the $this->db->get() function, so use whichever method you prefer.

+
+

$this->db->join()

+

Permits you to write the JOIN portion of your query:

+
$this->db->select('*');
+$this->db->from('blogs');
+$this->db->join('comments', 'comments.id = blogs.id');
+$query = $this->db->get();
+
+// Produces:
+// SELECT * FROM blogs JOIN comments ON comments.id = blogs.id
+
+
+

Multiple function calls can be made if you need several joins in one +query.

+

If you need a specific type of JOIN you can specify it via the third +parameter of the function. Options are: left, right, outer, inner, left +outer, and right outer.

+
$this->db->join('comments', 'comments.id = blogs.id', 'left');
+// Produces: LEFT JOIN comments ON comments.id = blogs.id
+
+
+
+
+

Looking for Specific Data

+

$this->db->where()

+

This function enables you to set WHERE clauses using one of four +methods:

+
+

Note

+

All values passed to this function are escaped automatically, +producing safer queries.

+
+
    +

  1. Simple key/value method:

    +
    +
    $this->db->where('name', $name); // Produces: WHERE name = 'Joe'
+
    +
    +

    Notice that the equal sign is added for you.

    +

    If you use multiple function calls they will be chained together with +AND between them:

    +
    $this->db->where('name', $name);
+$this->db->where('title', $title);
+$this->db->where('status', $status);
+// WHERE name = 'Joe' AND title = 'boss' AND status = 'active'
+
    +
    +
    +
    2. +

  2. Custom key/value method:

    +
    +

    You can include an operator in the first parameter in order to +control the comparison:

    +
    $this->db->where('name !=', $name);
+$this->db->where('id <', $id); // Produces: WHERE name != 'Joe' AND id < 45
+
    +
    +
    +
    3. +

  3. Associative array method:

    +
    +
    $array = array('name' => $name, 'title' => $title, 'status' => $status);
+$this->db->where($array);
+// Produces: WHERE name = 'Joe' AND title = 'boss' AND status = 'active'
+
    +
    +

    You can include your own operators using this method as well:

    +
    $array = array('name !=' => $name, 'id <' => $id, 'date >' => $date);
+$this->db->where($array);
+
    +
    +
    +
    4. +
  4. +
    Custom string:
    +

    You can write your own clauses manually:

    +
    $where = "name='Joe' AND status='boss' OR status='active'";
+$this->db->where($where);
+
    +
    +
    +
    +
    5. +
+

$this->db->where() accepts an optional third parameter. If you set it to +FALSE, CodeIgniter will not try to protect your field or table names.

+
$this->db->where('MATCH (field) AGAINST ("value")', NULL, FALSE);
+
+
+

$this->db->or_where()

+

This function is identical to the one above, except that multiple +instances are joined by OR:

+
$this->db->where('name !=', $name);
+$this->db->or_where('id >', $id);  // Produces: WHERE name != 'Joe' OR id > 50
+
+
+
+

Note

+

or_where() was formerly known as orwhere(), which has been +removed.

+
+

$this->db->where_in()

+

Generates a WHERE field IN (‘item’, ‘item’) SQL query joined with AND if +appropriate

+
$names = array('Frank', 'Todd', 'James');
+$this->db->where_in('username', $names);
+// Produces: WHERE username IN ('Frank', 'Todd', 'James')
+
+
+

$this->db->or_where_in()

+

Generates a WHERE field IN (‘item’, ‘item’) SQL query joined with OR if +appropriate

+
$names = array('Frank', 'Todd', 'James');
+$this->db->or_where_in('username', $names);
+// Produces: OR username IN ('Frank', 'Todd', 'James')
+
+
+

$this->db->where_not_in()

+

Generates a WHERE field NOT IN (‘item’, ‘item’) SQL query joined with +AND if appropriate

+
$names = array('Frank', 'Todd', 'James');
+$this->db->where_not_in('username', $names);
+// Produces: WHERE username NOT IN ('Frank', 'Todd', 'James')
+
+
+

$this->db->or_where_not_in()

+

Generates a WHERE field NOT IN (‘item’, ‘item’) SQL query joined with OR +if appropriate

+
$names = array('Frank', 'Todd', 'James');
+$this->db->or_where_not_in('username', $names);
+// Produces: OR username NOT IN ('Frank', 'Todd', 'James')
+
+
+
+
+

Looking for Similar Data

+

$this->db->like()

+

This method enables you to generate LIKE clauses, useful for doing +searches.

+
+

Note

+

All values passed to this method are escaped automatically.

+
+
    +

  1. Simple key/value method:

    +
    +
    $this->db->like('title', 'match');
+// Produces: WHERE `title` LIKE '%match%' ESCAPE '!'
+
    +
    +

    If you use multiple method calls they will be chained together with +AND between them:

    +
    $this->db->like('title', 'match');
+$this->db->like('body', 'match');
+// WHERE `title` LIKE '%match%' ESCAPE '!' AND  `body` LIKE '%match% ESCAPE '!'
+
    +
    +

    If you want to control where the wildcard (%) is placed, you can use +an optional third argument. Your options are ‘before’, ‘after’ and +‘both’ (which is the default).

    +
    $this->db->like('title', 'match', 'before');    // Produces: WHERE `title` LIKE '%match' ESCAPE '!'
+$this->db->like('title', 'match', 'after');     // Produces: WHERE `title` LIKE 'match%' ESCAPE '!'
+$this->db->like('title', 'match', 'both');      // Produces: WHERE `title` LIKE '%match%' ESCAPE '!'
+
    +
    +
    +
    2. +

  2. Associative array method:

    +
    +
    $array = array('title' => $match, 'page1' => $match, 'page2' => $match);
+$this->db->like($array);
+// WHERE `title` LIKE '%match%' ESCAPE '!' AND  `page1` LIKE '%match%' ESCAPE '!' AND  `page2` LIKE '%match%' ESCAPE '!'
+
    +
    +
    +
    3. +
+

$this->db->or_like()

+

This method is identical to the one above, except that multiple +instances are joined by OR:

+
$this->db->like('title', 'match'); $this->db->or_like('body', $match);
+// WHERE `title` LIKE '%match%' ESCAPE '!' OR  `body` LIKE '%match%' ESCAPE '!'
+
+
+
+

Note

+

or_like() was formerly known as orlike(), which has been removed.

+
+

$this->db->not_like()

+

This method is identical to like(), except that it generates +NOT LIKE statements:

+
$this->db->not_like('title', 'match');  // WHERE `title` NOT LIKE '%match% ESCAPE '!'
+
+
+

$this->db->or_not_like()

+

This method is identical to not_like(), except that multiple +instances are joined by OR:

+
$this->db->like('title', 'match');
+$this->db->or_not_like('body', 'match');
+// WHERE `title` LIKE '%match% OR  `body` NOT LIKE '%match%' ESCAPE '!'
+
+
+

$this->db->group_by()

+

Permits you to write the GROUP BY portion of your query:

+
$this->db->group_by("title"); // Produces: GROUP BY title
+
+
+

You can also pass an array of multiple values as well:

+
$this->db->group_by(array("title", "date"));  // Produces: GROUP BY title, date
+
+
+
+

Note

+

group_by() was formerly known as groupby(), which has been +removed.

+
+

$this->db->distinct()

+

Adds the “DISTINCT” keyword to a query

+
$this->db->distinct();
+$this->db->get('table'); // Produces: SELECT DISTINCT * FROM table
+
+
+

$this->db->having()

+

Permits you to write the HAVING portion of your query. There are 2 +possible syntaxes, 1 argument or 2:

+
$this->db->having('user_id = 45');  // Produces: HAVING user_id = 45
+$this->db->having('user_id',  45);  // Produces: HAVING user_id = 45
+
+
+

You can also pass an array of multiple values as well:

+
$this->db->having(array('title =' => 'My Title', 'id <' => $id));
+// Produces: HAVING title = 'My Title', id < 45
+
+
+

If you are using a database that CodeIgniter escapes queries for, you +can prevent escaping content by passing an optional third argument, and +setting it to FALSE.

+
$this->db->having('user_id',  45);  // Produces: HAVING `user_id` = 45 in some databases such as MySQL
+$this->db->having('user_id',  45, FALSE);  // Produces: HAVING user_id = 45
+
+
+

$this->db->or_having()

+

Identical to having(), only separates multiple clauses with “OR”.

+
+
+

Ordering results

+

$this->db->order_by()

+

Lets you set an ORDER BY clause.

+

The first parameter contains the name of the column you would like to order by.

+

The second parameter lets you set the direction of the result. +Options are ASC, DESC AND RANDOM.

+
$this->db->order_by('title', 'DESC');
+// Produces: ORDER BY `title` DESC
+
+
+

You can also pass your own string in the first parameter:

+
$this->db->order_by('title DESC, name ASC');
+// Produces: ORDER BY `title` DESC, `name` ASC
+
+
+

Or multiple function calls can be made if you need multiple fields.

+
$this->db->order_by('title', 'DESC');
+$this->db->order_by('name', 'ASC');
+// Produces: ORDER BY `title` DESC, `name` ASC
+
+
+

If you choose the RANDOM direction option, then the first parameters will +be ignored, unless you specify a numeric seed value.

+
$this->db->order_by('title', 'RANDOM');
+// Produces: ORDER BY RAND()
+
+$this->db->order_by(42, 'RANDOM');
+// Produces: ORDER BY RAND(42)
+
+
+
+

Note

+

order_by() was formerly known as orderby(), which has been +removed.

+
+
+

Note

+

Random ordering is not currently supported in Oracle and +will default to ASC instead.

+
+
+
+

Limiting or Counting Results

+

$this->db->limit()

+

Lets you limit the number of rows you would like returned by the query:

+
$this->db->limit(10);  // Produces: LIMIT 10
+
+
+

The second parameter lets you set a result offset.

+
$this->db->limit(10, 20);  // Produces: LIMIT 20, 10 (in MySQL.  Other databases have slightly different syntax)
+
+
+

$this->db->count_all_results()

+

Permits you to determine the number of rows in a particular Active +Record query. Queries will accept Query Builder restrictors such as +where(), or_where(), like(), or_like(), etc. Example:

+
echo $this->db->count_all_results('my_table');  // Produces an integer, like 25
+$this->db->like('title', 'match');
+$this->db->from('my_table');
+echo $this->db->count_all_results(); // Produces an integer, like 17
+
+
+

However, this method also resets any field values that you may have passed +to select(). If you need to keep them, you can pass FALSE as the +second parameter:

+
echo $this->db->count_all_results('my_table', FALSE);
+
+
+

$this->db->count_all()

+

Permits you to determine the number of rows in a particular table. +Submit the table name in the first parameter. Example:

+
echo $this->db->count_all('my_table');  // Produces an integer, like 25
+
+
+
+
+

Query grouping

+

Query grouping allows you to create groups of WHERE clauses by enclosing them in parentheses. This will allow +you to create queries with complex WHERE clauses. Nested groups are supported. Example:

+
$this->db->select('*')->from('my_table')
+        ->group_start()
+                ->where('a', 'a')
+                ->or_group_start()
+                        ->where('b', 'b')
+                        ->where('c', 'c')
+                ->group_end()
+        ->group_end()
+        ->where('d', 'd')
+->get();
+
+// Generates:
+// SELECT * FROM (`my_table`) WHERE ( `a` = 'a' OR ( `b` = 'b' AND `c` = 'c' ) ) AND `d` = 'd'
+
+
+
+

Note

+

groups need to be balanced, make sure every group_start() is matched by a group_end().

+
+

$this->db->group_start()

+

Starts a new group by adding an opening parenthesis to the WHERE clause of the query.

+

$this->db->or_group_start()

+

Starts a new group by adding an opening parenthesis to the WHERE clause of the query, prefixing it with ‘OR’.

+

$this->db->not_group_start()

+

Starts a new group by adding an opening parenthesis to the WHERE clause of the query, prefixing it with ‘NOT’.

+

$this->db->or_not_group_start()

+

Starts a new group by adding an opening parenthesis to the WHERE clause of the query, prefixing it with ‘OR NOT’.

+

$this->db->group_end()

+

Ends the current group by adding an closing parenthesis to the WHERE clause of the query.

+
+
+

Inserting Data

+

$this->db->insert()

+

Generates an insert string based on the data you supply, and runs the +query. You can either pass an array or an object to the +function. Here is an example using an array:

+
$data = array(
+        'title' => 'My title',
+        'name' => 'My Name',
+        'date' => 'My date'
+);
+
+$this->db->insert('mytable', $data);
+// Produces: INSERT INTO mytable (title, name, date) VALUES ('My title', 'My name', 'My date')
+
+
+

The first parameter will contain the table name, the second is an +associative array of values.

+

Here is an example using an object:

+
/*
+class Myclass {
+        public $title = 'My Title';
+        public $content = 'My Content';
+        public $date = 'My Date';
+}
+*/
+
+$object = new Myclass;
+$this->db->insert('mytable', $object);
+// Produces: INSERT INTO mytable (title, content, date) VALUES ('My Title', 'My Content', 'My Date')
+
+
+

The first parameter will contain the table name, the second is an +object.

+
+

Note

+

All values are escaped automatically producing safer queries.

+
+

$this->db->get_compiled_insert()

+

Compiles the insertion query just like $this->db->insert() but does not +run the query. This method simply returns the SQL query as a string.

+

Example:

+
$data = array(
+        'title' => 'My title',
+        'name'  => 'My Name',
+        'date'  => 'My date'
+);
+
+$sql = $this->db->set($data)->get_compiled_insert('mytable');
+echo $sql;
+
+// Produces string: INSERT INTO mytable (`title`, `name`, `date`) VALUES ('My title', 'My name', 'My date')
+
+
+

The second parameter enables you to set whether or not the query builder query +will be reset (by default it will be–just like $this->db->insert()):

+
echo $this->db->set('title', 'My Title')->get_compiled_insert('mytable', FALSE);
+
+// Produces string: INSERT INTO mytable (`title`) VALUES ('My Title')
+
+echo $this->db->set('content', 'My Content')->get_compiled_insert();
+
+// Produces string: INSERT INTO mytable (`title`, `content`) VALUES ('My Title', 'My Content')
+
+
+

The key thing to notice in the above example is that the second query did not +utilize $this->db->from() nor did it pass a table name into the first +parameter. The reason this worked is because the query has not been executed +using $this->db->insert() which resets values or reset directly using +$this->db->reset_query().

+
+

Note

+

This method doesn’t work for batched inserts.

+
+

$this->db->insert_batch()

+

Generates an insert string based on the data you supply, and runs the +query. You can either pass an array or an object to the +function. Here is an example using an array:

+
$data = array(
+        array(
+                'title' => 'My title',
+                'name' => 'My Name',
+                'date' => 'My date'
+        ),
+        array(
+                'title' => 'Another title',
+                'name' => 'Another Name',
+                'date' => 'Another date'
+        )
+);
+
+$this->db->insert_batch('mytable', $data);
+// Produces: INSERT INTO mytable (title, name, date) VALUES ('My title', 'My name', 'My date'),  ('Another title', 'Another name', 'Another date')
+
+
+

The first parameter will contain the table name, the second is an +associative array of values.

+
+

Note

+

All values are escaped automatically producing safer queries.

+
+
+
+

Updating Data

+

$this->db->replace()

+

This method executes a REPLACE statement, which is basically the SQL +standard for (optional) DELETE + INSERT, using PRIMARY and UNIQUE +keys as the determining factor. +In our case, it will save you from the need to implement complex +logics with different combinations of select(), update(), +delete() and insert() calls.

+

Example:

+
$data = array(
+        'title' => 'My title',
+        'name'  => 'My Name',
+        'date'  => 'My date'
+);
+
+$this->db->replace('table', $data);
+
+// Executes: REPLACE INTO mytable (title, name, date) VALUES ('My title', 'My name', 'My date')
+
+
+

In the above example, if we assume that the title field is our primary +key, then if a row containing ‘My title’ as the title value, that row +will be deleted with our new row data replacing it.

+

Usage of the set() method is also allowed and all fields are +automatically escaped, just like with insert().

+

$this->db->set()

+

This function enables you to set values for inserts or updates.

+

It can be used instead of passing a data array directly to the insert +or update functions:

+
$this->db->set('name', $name);
+$this->db->insert('mytable');  // Produces: INSERT INTO mytable (`name`) VALUES ('{$name}')
+
+
+

If you use multiple function called they will be assembled properly +based on whether you are doing an insert or an update:

+
$this->db->set('name', $name);
+$this->db->set('title', $title);
+$this->db->set('status', $status);
+$this->db->insert('mytable');
+
+
+

set() will also accept an optional third parameter ($escape), that +will prevent data from being escaped if set to FALSE. To illustrate the +difference, here is set() used both with and without the escape +parameter.

+
$this->db->set('field', 'field+1', FALSE);
+$this->db->where('id', 2);
+$this->db->update('mytable'); // gives UPDATE mytable SET field = field+1 WHERE id = 2
+
+$this->db->set('field', 'field+1');
+$this->db->where('id', 2);
+$this->db->update('mytable'); // gives UPDATE `mytable` SET `field` = 'field+1' WHERE `id` = 2
+
+
+

You can also pass an associative array to this function:

+
$array = array(
+        'name' => $name,
+        'title' => $title,
+        'status' => $status
+);
+
+$this->db->set($array);
+$this->db->insert('mytable');
+
+
+

Or an object:

+
/*
+class Myclass {
+        public $title = 'My Title';
+        public $content = 'My Content';
+        public $date = 'My Date';
+}
+*/
+
+$object = new Myclass;
+$this->db->set($object);
+$this->db->insert('mytable');
+
+
+

$this->db->update()

+

Generates an update string and runs the query based on the data you +supply. You can pass an array or an object to the function. Here +is an example using an array:

+
$data = array(
+        'title' => $title,
+        'name' => $name,
+        'date' => $date
+);
+
+$this->db->where('id', $id);
+$this->db->update('mytable', $data);
+// Produces:
+//
+//      UPDATE mytable
+//      SET title = '{$title}', name = '{$name}', date = '{$date}'
+//      WHERE id = $id
+
+
+

Or you can supply an object:

+
/*
+class Myclass {
+        public $title = 'My Title';
+        public $content = 'My Content';
+        public $date = 'My Date';
+}
+*/
+
+$object = new Myclass;
+$this->db->where('id', $id);
+$this->db->update('mytable', $object);
+// Produces:
+//
+// UPDATE `mytable`
+// SET `title` = '{$title}', `name` = '{$name}', `date` = '{$date}'
+// WHERE id = `$id`
+
+
+
+

Note

+

All values are escaped automatically producing safer queries.

+
+

You’ll notice the use of the $this->db->where() function, enabling you +to set the WHERE clause. You can optionally pass this information +directly into the update function as a string:

+
$this->db->update('mytable', $data, "id = 4");
+
+
+

Or as an array:

+
$this->db->update('mytable', $data, array('id' => $id));
+
+
+

You may also use the $this->db->set() function described above when +performing updates.

+

$this->db->update_batch()

+

Generates an update string based on the data you supply, and runs the query. +You can either pass an array or an object to the function. +Here is an example using an array:

+
$data = array(
+   array(
+      'title' => 'My title' ,
+      'name' => 'My Name 2' ,
+      'date' => 'My date 2'
+   ),
+   array(
+      'title' => 'Another title' ,
+      'name' => 'Another Name 2' ,
+      'date' => 'Another date 2'
+   )
+);
+
+$this->db->update_batch('mytable', $data, 'title');
+
+// Produces:
+// UPDATE `mytable` SET `name` = CASE
+// WHEN `title` = 'My title' THEN 'My Name 2'
+// WHEN `title` = 'Another title' THEN 'Another Name 2'
+// ELSE `name` END,
+// `date` = CASE
+// WHEN `title` = 'My title' THEN 'My date 2'
+// WHEN `title` = 'Another title' THEN 'Another date 2'
+// ELSE `date` END
+// WHERE `title` IN ('My title','Another title')
+
+
+

The first parameter will contain the table name, the second is an associative +array of values, the third parameter is the where key.

+
+

Note

+

All values are escaped automatically producing safer queries.

+
+
+

Note

+

affected_rows() won’t give you proper results with this method, +due to the very nature of how it works. Instead, update_batch() +returns the number of rows affected.

+
+

$this->db->get_compiled_update()

+

This works exactly the same way as $this->db->get_compiled_insert() except +that it produces an UPDATE SQL string instead of an INSERT SQL string.

+

For more information view documentation for $this->db->get_compiled_insert().

+
+

Note

+

This method doesn’t work for batched updates.

+
+
+
+

Deleting Data

+

$this->db->delete()

+

Generates a delete SQL string and runs the query.

+
$this->db->delete('mytable', array('id' => $id));  // Produces: // DELETE FROM mytable  // WHERE id = $id
+
+
+

The first parameter is the table name, the second is the where clause. +You can also use the where() or or_where() functions instead of passing +the data to the second parameter of the function:

+
$this->db->where('id', $id);
+$this->db->delete('mytable');
+
+// Produces:
+// DELETE FROM mytable
+// WHERE id = $id
+
+
+

An array of table names can be passed into delete() if you would like to +delete data from more than 1 table.

+
$tables = array('table1', 'table2', 'table3');
+$this->db->where('id', '5');
+$this->db->delete($tables);
+
+
+

If you want to delete all data from a table, you can use the truncate() +function, or empty_table().

+

$this->db->empty_table()

+

Generates a delete SQL string and runs the +query.:

+
$this->db->empty_table('mytable'); // Produces: DELETE FROM mytable
+
+
+

$this->db->truncate()

+

Generates a truncate SQL string and runs the query.

+
$this->db->from('mytable');
+$this->db->truncate();
+
+// or
+
+$this->db->truncate('mytable');
+
+// Produce:
+// TRUNCATE mytable
+
+
+
+

Note

+

If the TRUNCATE command isn’t available, truncate() will +execute as “DELETE FROM table”.

+
+

$this->db->get_compiled_delete()

+

This works exactly the same way as $this->db->get_compiled_insert() except +that it produces a DELETE SQL string instead of an INSERT SQL string.

+

For more information view documentation for $this->db->get_compiled_insert().

+
+
+

Method Chaining

+

Method chaining allows you to simplify your syntax by connecting +multiple functions. Consider this example:

+
$query = $this->db->select('title')
+                ->where('id', $id)
+                ->limit(10, 20)
+                ->get('mytable');
+
+
+
+
+

Query Builder Caching

+

While not “true” caching, Query Builder enables you to save (or “cache”) +certain parts of your queries for reuse at a later point in your +script’s execution. Normally, when an Query Builder call is completed, +all stored information is reset for the next call. With caching, you can +prevent this reset, and reuse information easily.

+

Cached calls are cumulative. If you make 2 cached select() calls, and +then 2 uncached select() calls, this will result in 4 select() calls. +There are three Caching functions available:

+

$this->db->start_cache()

+

This function must be called to begin caching. All Query Builder queries +of the correct type (see below for supported queries) are stored for +later use.

+

$this->db->stop_cache()

+

This function can be called to stop caching.

+

$this->db->flush_cache()

+

This function deletes all items from the Query Builder cache.

+
+

An example of caching

+

Here’s a usage example:

+
$this->db->start_cache();
+$this->db->select('field1');
+$this->db->stop_cache();
+$this->db->get('tablename');
+//Generates: SELECT `field1` FROM (`tablename`)
+
+$this->db->select('field2');
+$this->db->get('tablename');
+//Generates:  SELECT `field1`, `field2` FROM (`tablename`)
+
+$this->db->flush_cache();
+$this->db->select('field2');
+$this->db->get('tablename');
+//Generates:  SELECT `field2` FROM (`tablename`)
+
+
+
+

Note

+

The following statements can be cached: select, from, join, +where, like, group_by, having, order_by

+
+
+
+
+

Resetting Query Builder

+

$this->db->reset_query()

+

Resetting Query Builder allows you to start fresh with your query without +executing it first using a method like $this->db->get() or $this->db->insert(). +Just like the methods that execute a query, this will not reset items you’ve +cached using Query Builder Caching.

+

This is useful in situations where you are using Query Builder to generate SQL +(ex. $this->db->get_compiled_select()) but then choose to, for instance, +run the query:

+
// Note that the second parameter of the get_compiled_select method is FALSE
+$sql = $this->db->select(array('field1','field2'))
+                                ->where('field3',5)
+                                ->get_compiled_select('mytable', FALSE);
+
+// ...
+// Do something crazy with the SQL code... like add it to a cron script for
+// later execution or something...
+// ...
+
+$data = $this->db->get()->result_array();
+
+// Would execute and return an array of results of the following query:
+// SELECT field1, field1 from mytable where field3 = 5;
+
+
+
+

Note

+

Double calls to get_compiled_select() while you’re using the +Query Builder Caching functionality and NOT resetting your queries +will results in the cache being merged twice. That in turn will +i.e. if you’re caching a select() - select the same field twice.

+
+
+
+

Class Reference

+
+
+class CI_DB_query_builder
+
+
+reset_query()
+
+++ + + + + + +
Returns:CI_DB_query_builder instance (method chaining)
Return type:CI_DB_query_builder
+

Resets the current Query Builder state. Useful when you want +to build a query that can be cancelled under certain conditions.

+
+ +
+
+start_cache()
+
+++ + + + + + +
Returns:CI_DB_query_builder instance (method chaining)
Return type:CI_DB_query_builder
+

Starts the Query Builder cache.

+
+ +
+
+stop_cache()
+
+++ + + + + + +
Returns:CI_DB_query_builder instance (method chaining)
Return type:CI_DB_query_builder
+

Stops the Query Builder cache.

+
+ +
+
+flush_cache()
+
+++ + + + + + +
Returns:CI_DB_query_builder instance (method chaining)
Return type:CI_DB_query_builder
+

Empties the Query Builder cache.

+
+ +
+
+set_dbprefix([$prefix = ''])
+
+++ + + + + + + + +
Parameters:
    +
  • $prefix (string) – The new prefix to use
    • +
+
Returns:

The DB prefix in use

+
Return type:

string

+
+

Sets the database prefix, without having to reconnect.

+
+ +
+
+dbprefix([$table = ''])
+
+++ + + + + + + + +
Parameters:
    +
  • $table (string) – The table name to prefix
    • +
+
Returns:

The prefixed table name

+
Return type:

string

+
+

Prepends a database prefix, if one exists in configuration.

+
+ +
+
+count_all_results([$table = ''[, $reset = TRUE]])
+
+++ + + + + + + + +
Parameters:
    +
  • $table (string) – Table name
    • +
  • $reset (bool) – Whether to reset values for SELECTs
    • +
+
Returns:

Number of rows in the query result

+
Return type:

int

+
+

Generates a platform-specific query string that counts +all records returned by an Query Builder query.

+
+ +
+
+get([$table = ''[, $limit = NULL[, $offset = NULL]]])
+
+++ + + + + + + + +
Parameters:
    +
  • $table (string) – The table to query
    • +
  • $limit (int) – The LIMIT clause
    • +
  • $offset (int) – The OFFSET clause
    • +
+
Returns:

CI_DB_result instance (method chaining)

+
Return type:

CI_DB_result

+
+

Compiles and runs SELECT statement based on the already +called Query Builder methods.

+
+ +
+
+get_where([$table = ''[, $where = NULL[, $limit = NULL[, $offset = NULL]]]])
+
+++ + + + + + + + +
Parameters:
    +
  • $table (mixed) – The table(s) to fetch data from; string or array
    • +
  • $where (string) – The WHERE clause
    • +
  • $limit (int) – The LIMIT clause
    • +
  • $offset (int) – The OFFSET clause
    • +
+
Returns:

CI_DB_result instance (method chaining)

+
Return type:

CI_DB_result

+
+

Same as get(), but also allows the WHERE to be added directly.

+
+ +
+
+select([$select = '*'[, $escape = NULL]])
+
+++ + + + + + + + +
Parameters:
    +
  • $select (string) – The SELECT portion of a query
    • +
  • $escape (bool) – Whether to escape values and identifiers
    • +
+
Returns:

CI_DB_query_builder instance (method chaining)

+
Return type:

CI_DB_query_builder

+
+

Adds a SELECT clause to a query.

+
+ +
+
+select_avg([$select = ''[, $alias = '']])
+
+++ + + + + + + + +
Parameters:
    +
  • $select (string) – Field to compute the average of
    • +
  • $alias (string) – Alias for the resulting value name
    • +
+
Returns:

CI_DB_query_builder instance (method chaining)

+
Return type:

CI_DB_query_builder

+
+

Adds a SELECT AVG(field) clause to a query.

+
+ +
+
+select_max([$select = ''[, $alias = '']])
+
+++ + + + + + + + +
Parameters:
    +
  • $select (string) – Field to compute the maximum of
    • +
  • $alias (string) – Alias for the resulting value name
    • +
+
Returns:

CI_DB_query_builder instance (method chaining)

+
Return type:

CI_DB_query_builder

+
+

Adds a SELECT MAX(field) clause to a query.

+
+ +
+
+select_min([$select = ''[, $alias = '']])
+
+++ + + + + + + + +
Parameters:
    +
  • $select (string) – Field to compute the minimum of
    • +
  • $alias (string) – Alias for the resulting value name
    • +
+
Returns:

CI_DB_query_builder instance (method chaining)

+
Return type:

CI_DB_query_builder

+
+

Adds a SELECT MIN(field) clause to a query.

+
+ +
+
+select_sum([$select = ''[, $alias = '']])
+
+++ + + + + + + + +
Parameters:
    +
  • $select (string) – Field to compute the sum of
    • +
  • $alias (string) – Alias for the resulting value name
    • +
+
Returns:

CI_DB_query_builder instance (method chaining)

+
Return type:

CI_DB_query_builder

+
+

Adds a SELECT SUM(field) clause to a query.

+
+ +
+
+distinct([$val = TRUE])
+
+++ + + + + + + + +
Parameters:
    +
  • $val (bool) – Desired value of the “distinct” flag
    • +
+
Returns:

CI_DB_query_builder instance (method chaining)

+
Return type:

CI_DB_query_builder

+
+

Sets a flag which tells the query builder to add +a DISTINCT clause to the SELECT portion of the query.

+
+ +
+
+from($from)
+
+++ + + + + + + + +
Parameters:
    +
  • $from (mixed) – Table name(s); string or array
    • +
+
Returns:

CI_DB_query_builder instance (method chaining)

+
Return type:

CI_DB_query_builder

+
+

Specifies the FROM clause of a query.

+
+ +
+
+join($table, $cond[, $type = ''[, $escape = NULL]])
+
+++ + + + + + + + +
Parameters:
    +
  • $table (string) – Table name to join
    • +
  • $cond (string) – The JOIN ON condition
    • +
  • $type (string) – The JOIN type
    • +
  • $escape (bool) – Whether to escape values and identifiers
    • +
+
Returns:

CI_DB_query_builder instance (method chaining)

+
Return type:

CI_DB_query_builder

+
+

Adds a JOIN clause to a query.

+
+ +
+
+where($key[, $value = NULL[, $escape = NULL]])
+
+++ + + + + + + + +
Parameters:
    +
  • $key (mixed) – Name of field to compare, or associative array
    • +
  • $value (mixed) – If a single key, compared to this value
    • +
  • $escape (bool) – Whether to escape values and identifiers
    • +
+
Returns:

DB_query_builder instance

+
Return type:

object

+
+

Generates the WHERE portion of the query. +Separates multiple calls with ‘AND’.

+
+ +
+
+or_where($key[, $value = NULL[, $escape = NULL]])
+
+++ + + + + + + + +
Parameters:
    +
  • $key (mixed) – Name of field to compare, or associative array
    • +
  • $value (mixed) – If a single key, compared to this value
    • +
  • $escape (bool) – Whether to escape values and identifiers
    • +
+
Returns:

DB_query_builder instance

+
Return type:

object

+
+

Generates the WHERE portion of the query. +Separates multiple calls with ‘OR’.

+
+ +
+
+or_where_in([$key = NULL[, $values = NULL[, $escape = NULL]]])
+
+++ + + + + + + + +
Parameters:
    +
  • $key (string) – The field to search
    • +
  • $values (array) – The values searched on
    • +
  • $escape (bool) – Whether to escape values and identifiers
    • +
+
Returns:

DB_query_builder instance

+
Return type:

object

+
+

Generates a WHERE field IN(‘item’, ‘item’) SQL query, +joined with ‘OR’ if appropriate.

+
+ +
+
+or_where_not_in([$key = NULL[, $values = NULL[, $escape = NULL]]])
+
+++ + + + + + + + +
Parameters:
    +
  • $key (string) – The field to search
    • +
  • $values (array) – The values searched on
    • +
  • $escape (bool) – Whether to escape values and identifiers
    • +
+
Returns:

DB_query_builder instance

+
Return type:

object

+
+

Generates a WHERE field NOT IN(‘item’, ‘item’) SQL query, +joined with ‘OR’ if appropriate.

+
+ +
+
+where_in([$key = NULL[, $values = NULL[, $escape = NULL]]])
+
+++ + + + + + + + +
Parameters:
    +
  • $key (string) – Name of field to examine
    • +
  • $values (array) – Array of target values
    • +
  • $escape (bool) – Whether to escape values and identifiers
    • +
+
Returns:

DB_query_builder instance

+
Return type:

object

+
+

Generates a WHERE field IN(‘item’, ‘item’) SQL query, +joined with ‘AND’ if appropriate.

+
+ +
+
+where_not_in([$key = NULL[, $values = NULL[, $escape = NULL]]])
+
+++ + + + + + + + +
Parameters:
    +
  • $key (string) – Name of field to examine
    • +
  • $values (array) – Array of target values
    • +
  • $escape (bool) – Whether to escape values and identifiers
    • +
+
Returns:

DB_query_builder instance

+
Return type:

object

+
+

Generates a WHERE field NOT IN(‘item’, ‘item’) SQL query, +joined with ‘AND’ if appropriate.

+
+ +
+
+group_start()
+
+++ + + + + + +
Returns:CI_DB_query_builder instance (method chaining)
Return type:CI_DB_query_builder
+

Starts a group expression, using ANDs for the conditions inside it.

+
+ +
+
+or_group_start()
+
+++ + + + + + +
Returns:CI_DB_query_builder instance (method chaining)
Return type:CI_DB_query_builder
+

Starts a group expression, using ORs for the conditions inside it.

+
+ +
+
+not_group_start()
+
+++ + + + + + +
Returns:CI_DB_query_builder instance (method chaining)
Return type:CI_DB_query_builder
+

Starts a group expression, using AND NOTs for the conditions inside it.

+
+ +
+
+or_not_group_start()
+
+++ + + + + + +
Returns:CI_DB_query_builder instance (method chaining)
Return type:CI_DB_query_builder
+

Starts a group expression, using OR NOTs for the conditions inside it.

+
+ +
+
+group_end()
+
+++ + + + + + +
Returns:DB_query_builder instance
Return type:object
+

Ends a group expression.

+
+ +
+
+like($field[, $match = ''[, $side = 'both'[, $escape = NULL]]])
+
+++ + + + + + + + +
Parameters:
    +
  • $field (string) – Field name
    • +
  • $match (string) – Text portion to match
    • +
  • $side (string) – Which side of the expression to put the ‘%’ wildcard on
    • +
  • $escape (bool) – Whether to escape values and identifiers
    • +
+
Returns:

CI_DB_query_builder instance (method chaining)

+
Return type:

CI_DB_query_builder

+
+

Adds a LIKE clause to a query, separating multiple calls with AND.

+
+ +
+
+or_like($field[, $match = ''[, $side = 'both'[, $escape = NULL]]])
+
+++ + + + + + + + +
Parameters:
    +
  • $field (string) – Field name
    • +
  • $match (string) – Text portion to match
    • +
  • $side (string) – Which side of the expression to put the ‘%’ wildcard on
    • +
  • $escape (bool) – Whether to escape values and identifiers
    • +
+
Returns:

CI_DB_query_builder instance (method chaining)

+
Return type:

CI_DB_query_builder

+
+

Adds a LIKE clause to a query, separating multiple class with OR.

+
+ +
+
+not_like($field[, $match = ''[, $side = 'both'[, $escape = NULL]]])
+
+++ + + + + + + + +
Parameters:
    +
  • $field (string) – Field name
    • +
  • $match (string) – Text portion to match
    • +
  • $side (string) – Which side of the expression to put the ‘%’ wildcard on
    • +
  • $escape (bool) – Whether to escape values and identifiers
    • +
+
Returns:

CI_DB_query_builder instance (method chaining)

+
Return type:

CI_DB_query_builder

+
+

Adds a NOT LIKE clause to a query, separating multiple calls with AND.

+
+ +
+
+or_not_like($field[, $match = ''[, $side = 'both'[, $escape = NULL]]])
+
+++ + + + + + + + +
Parameters:
    +
  • $field (string) – Field name
    • +
  • $match (string) – Text portion to match
    • +
  • $side (string) – Which side of the expression to put the ‘%’ wildcard on
    • +
  • $escape (bool) – Whether to escape values and identifiers
    • +
+
Returns:

CI_DB_query_builder instance (method chaining)

+
Return type:

CI_DB_query_builder

+
+

Adds a NOT LIKE clause to a query, separating multiple calls with OR.

+
+ +
+
+having($key[, $value = NULL[, $escape = NULL]])
+
+++ + + + + + + + +
Parameters:
    +
  • $key (mixed) – Identifier (string) or associative array of field/value pairs
    • +
  • $value (string) – Value sought if $key is an identifier
    • +
  • $escape (string) – Whether to escape values and identifiers
    • +
+
Returns:

CI_DB_query_builder instance (method chaining)

+
Return type:

CI_DB_query_builder

+
+

Adds a HAVING clause to a query, separating multiple calls with AND.

+
+ +
+
+or_having($key[, $value = NULL[, $escape = NULL]])
+
+++ + + + + + + + +
Parameters:
    +
  • $key (mixed) – Identifier (string) or associative array of field/value pairs
    • +
  • $value (string) – Value sought if $key is an identifier
    • +
  • $escape (string) – Whether to escape values and identifiers
    • +
+
Returns:

CI_DB_query_builder instance (method chaining)

+
Return type:

CI_DB_query_builder

+
+

Adds a HAVING clause to a query, separating multiple calls with OR.

+
+ +
+
+group_by($by[, $escape = NULL])
+
+++ + + + + + + + +
Parameters:
    +
  • $by (mixed) – Field(s) to group by; string or array
    • +
+
Returns:

CI_DB_query_builder instance (method chaining)

+
Return type:

CI_DB_query_builder

+
+

Adds a GROUP BY clause to a query.

+
+ +
+
+order_by($orderby[, $direction = ''[, $escape = NULL]])
+
+++ + + + + + + + +
Parameters:
    +
  • $orderby (string) – Field to order by
    • +
  • $direction (string) – The order requested - ASC, DESC or random
    • +
  • $escape (bool) – Whether to escape values and identifiers
    • +
+
Returns:

CI_DB_query_builder instance (method chaining)

+
Return type:

CI_DB_query_builder

+
+

Adds an ORDER BY clause to a query.

+
+ +
+
+limit($value[, $offset = 0])
+
+++ + + + + + + + +
Parameters:
    +
  • $value (int) – Number of rows to limit the results to
    • +
  • $offset (int) – Number of rows to skip
    • +
+
Returns:

CI_DB_query_builder instance (method chaining)

+
Return type:

CI_DB_query_builder

+
+

Adds LIMIT and OFFSET clauses to a query.

+
+ +
+
+offset($offset)
+
+++ + + + + + + + +
Parameters:
    +
  • $offset (int) – Number of rows to skip
    • +
+
Returns:

CI_DB_query_builder instance (method chaining)

+
Return type:

CI_DB_query_builder

+
+

Adds an OFFSET clause to a query.

+
+ +
+
+set($key[, $value = ''[, $escape = NULL]])
+
+++ + + + + + + + +
Parameters:
    +
  • $key (mixed) – Field name, or an array of field/value pairs
    • +
  • $value (string) – Field value, if $key is a single field
    • +
  • $escape (bool) – Whether to escape values and identifiers
    • +
+
Returns:

CI_DB_query_builder instance (method chaining)

+
Return type:

CI_DB_query_builder

+
+

Adds field/value pairs to be passed later to insert(), +update() or replace().

+
+ +
+
+insert([$table = ''[, $set = NULL[, $escape = NULL]]])
+
+++ + + + + + + + +
Parameters:
    +
  • $table (string) – Table name
    • +
  • $set (array) – An associative array of field/value pairs
    • +
  • $escape (bool) – Whether to escape values and identifiers
    • +
+
Returns:

TRUE on success, FALSE on failure

+
Return type:

bool

+
+

Compiles and executes an INSERT statement.

+
+ +
+
+insert_batch($table[, $set = NULL[, $escape = NULL[, $batch_size = 100]]])
+
+++ + + + + + + + +
Parameters:
    +
  • $table (string) – Table name
    • +
  • $set (array) – Data to insert
    • +
  • $escape (bool) – Whether to escape values and identifiers
    • +
  • $batch_size (int) – Count of rows to insert at once
    • +
+
Returns:

Number of rows inserted or FALSE on failure

+
Return type:

mixed

+
+

Compiles and executes batch INSERT statements.

+
+

Note

+

When more than $batch_size rows are provided, multiple +INSERT queries will be executed, each trying to insert +up to $batch_size rows.

+
+
+ +
+
+set_insert_batch($key[, $value = ''[, $escape = NULL]])
+
+++ + + + + + + + +
Parameters:
    +
  • $key (mixed) – Field name or an array of field/value pairs
    • +
  • $value (string) – Field value, if $key is a single field
    • +
  • $escape (bool) – Whether to escape values and identifiers
    • +
+
Returns:

CI_DB_query_builder instance (method chaining)

+
Return type:

CI_DB_query_builder

+
+

Adds field/value pairs to be inserted in a table later via insert_batch().

+
+ +
+
+update([$table = ''[, $set = NULL[, $where = NULL[, $limit = NULL]]]])
+
+++ + + + + + + + +
Parameters:
    +
  • $table (string) – Table name
    • +
  • $set (array) – An associative array of field/value pairs
    • +
  • $where (string) – The WHERE clause
    • +
  • $limit (int) – The LIMIT clause
    • +
+
Returns:

TRUE on success, FALSE on failure

+
Return type:

bool

+
+

Compiles and executes an UPDATE statement.

+
+ +
+
+update_batch($table[, $set = NULL[, $value = NULL[, $batch_size = 100]]])
+
+++ + + + + + + + +
Parameters:
    +
  • $table (string) – Table name
    • +
  • $set (array) – Field name, or an associative array of field/value pairs
    • +
  • $value (string) – Field value, if $set is a single field
    • +
  • $batch_size (int) – Count of conditions to group in a single query
    • +
+
Returns:

Number of rows updated or FALSE on failure

+
Return type:

mixed

+
+

Compiles and executes batch UPDATE statements.

+
+

Note

+

When more than $batch_size field/value pairs are provided, +multiple queries will be executed, each handling up to +$batch_size field/value pairs.

+
+
+ +
+
+set_update_batch($key[, $value = ''[, $escape = NULL]])
+
+++ + + + + + + + +
Parameters:
    +
  • $key (mixed) – Field name or an array of field/value pairs
    • +
  • $value (string) – Field value, if $key is a single field
    • +
  • $escape (bool) – Whether to escape values and identifiers
    • +
+
Returns:

CI_DB_query_builder instance (method chaining)

+
Return type:

CI_DB_query_builder

+
+

Adds field/value pairs to be updated in a table later via update_batch().

+
+ +
+
+replace([$table = ''[, $set = NULL]])
+
+++ + + + + + + + +
Parameters:
    +
  • $table (string) – Table name
    • +
  • $set (array) – An associative array of field/value pairs
    • +
+
Returns:

TRUE on success, FALSE on failure

+
Return type:

bool

+
+

Compiles and executes a REPLACE statement.

+
+ +
+
+delete([$table = ''[, $where = ''[, $limit = NULL[, $reset_data = TRUE]]]])
+
+++ + + + + + + + +
Parameters:
    +
  • $table (mixed) – The table(s) to delete from; string or array
    • +
  • $where (string) – The WHERE clause
    • +
  • $limit (int) – The LIMIT clause
    • +
  • $reset_data (bool) – TRUE to reset the query “write” clause
    • +
+
Returns:

CI_DB_query_builder instance (method chaining) or FALSE on failure

+
Return type:

mixed

+
+

Compiles and executes a DELETE query.

+
+ +
+
+truncate([$table = ''])
+
+++ + + + + + + + +
Parameters:
    +
  • $table (string) – Table name
    • +
+
Returns:

TRUE on success, FALSE on failure

+
Return type:

bool

+
+

Executes a TRUNCATE statement on a table.

+
+

Note

+

If the database platform in use doesn’t support TRUNCATE, +a DELETE statement will be used instead.

+
+
+ +
+
+empty_table([$table = ''])
+
+++ + + + + + + + +
Parameters:
    +
  • $table (string) – Table name
    • +
+
Returns:

TRUE on success, FALSE on failure

+
Return type:

bool

+
+

Deletes all records from a table via a DELETE statement.

+
+ +
+
+get_compiled_select([$table = ''[, $reset = TRUE]])
+
+++ + + + + + + + +
Parameters:
    +
  • $table (string) – Table name
    • +
  • $reset (bool) – Whether to reset the current QB values or not
    • +
+
Returns:

The compiled SQL statement as a string

+
Return type:

string

+
+

Compiles a SELECT statement and returns it as a string.

+
+ +
+
+get_compiled_insert([$table = ''[, $reset = TRUE]])
+
+++ + + + + + + + +
Parameters:
    +
  • $table (string) – Table name
    • +
  • $reset (bool) – Whether to reset the current QB values or not
    • +
+
Returns:

The compiled SQL statement as a string

+
Return type:

string

+
+

Compiles an INSERT statement and returns it as a string.

+
+ +
+
+get_compiled_update([$table = ''[, $reset = TRUE]])
+
+++ + + + + + + + +
Parameters:
    +
  • $table (string) – Table name
    • +
  • $reset (bool) – Whether to reset the current QB values or not
    • +
+
Returns:

The compiled SQL statement as a string

+
Return type:

string

+
+

Compiles an UPDATE statement and returns it as a string.

+
+ +
+
+get_compiled_delete([$table = ''[, $reset = TRUE]])
+
+++ + + + + + + + +
Parameters:
    +
  • $table (string) – Table name
    • +
  • $reset (bool) – Whether to reset the current QB values or not
    • +
+
Returns:

The compiled SQL statement as a string

+
Return type:

string

+
+

Compiles a DELETE statement and returns it as a string.

+
+ +
+ +
+
+ + +
+
+ + + + +
+ +
+

+ © Copyright 2014 - 2018, British Columbia Institute of Technology. + Last updated on Mar 22, 2018. +

+
+ + Built with Sphinx using a theme provided by Read the Docs. + +
+
+
+ +
+ +
+ + + + + + + + + + + + + + + + + + + + + + + + \ No newline at end of file diff --git a/user_guide/database/results.html b/user_guide/database/results.html new file mode 100644 index 000000000..5b0d5c9a5 --- /dev/null +++ b/user_guide/database/results.html @@ -0,0 +1,1231 @@ + + + + + + + + + + Generating Query Results — CodeIgniter 3.1.8 documentation + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +
+ + + + +
+ + + + + + +
+
+
+ +
+
+
+ +
+

Generating Query Results

+

There are several ways to generate query results:

+ +
+

Result Arrays

+

result()

+

This method returns the query result as an array of objects, or +an empty array on failure. Typically you’ll use this in a foreach +loop, like this:

+
$query = $this->db->query("YOUR QUERY");
+
+foreach ($query->result() as $row)
+{
+        echo $row->title;
+        echo $row->name;
+        echo $row->body;
+}
+
+
+

The above method is an alias of result_object().

+

You can also pass a string to result() which represents a class to +instantiate for each result object (note: this class must be loaded)

+
$query = $this->db->query("SELECT * FROM users;");
+
+foreach ($query->result('User') as $user)
+{
+        echo $user->name; // access attributes
+        echo $user->reverse_name(); // or methods defined on the 'User' class
+}
+
+
+

result_array()

+

This method returns the query result as a pure array, or an empty +array when no result is produced. Typically you’ll use this in a foreach +loop, like this:

+
$query = $this->db->query("YOUR QUERY");
+
+foreach ($query->result_array() as $row)
+{
+        echo $row['title'];
+        echo $row['name'];
+        echo $row['body'];
+}
+
+
+
+
+

Result Rows

+

row()

+

This method returns a single result row. If your query has more than +one row, it returns only the first row. The result is returned as an +object. Here’s a usage example:

+
$query = $this->db->query("YOUR QUERY");
+
+$row = $query->row();
+
+if (isset($row))
+{
+        echo $row->title;
+        echo $row->name;
+        echo $row->body;
+}
+
+
+

If you want a specific row returned you can submit the row number as a +digit in the first parameter:

+
$row = $query->row(5);
+
+
+

You can also add a second String parameter, which is the name of a class +to instantiate the row with:

+
$query = $this->db->query("SELECT * FROM users LIMIT 1;");
+$row = $query->row(0, 'User');
+
+echo $row->name; // access attributes
+echo $row->reverse_name(); // or methods defined on the 'User' class
+
+
+

row_array()

+

Identical to the above row() method, except it returns an array. +Example:

+
$query = $this->db->query("YOUR QUERY");
+
+$row = $query->row_array();
+
+if (isset($row))
+{
+        echo $row['title'];
+        echo $row['name'];
+        echo $row['body'];
+}
+
+
+

If you want a specific row returned you can submit the row number as a +digit in the first parameter:

+
$row = $query->row_array(5);
+
+
+

In addition, you can walk forward/backwards/first/last through your +results using these variations:

+
+
+
$row = $query->first_row()
+
$row = $query->last_row()
+
$row = $query->next_row()
+
$row = $query->previous_row()
+
+
+

By default they return an object unless you put the word “array” in the +parameter:

+
+
+
$row = $query->first_row(‘array’)
+
$row = $query->last_row(‘array’)
+
$row = $query->next_row(‘array’)
+
$row = $query->previous_row(‘array’)
+
+
+
+

Note

+

All the methods above will load the whole result into memory +(prefetching). Use unbuffered_row() for processing large +result sets.

+
+

unbuffered_row()

+

This method returns a single result row without prefetching the whole +result in memory as row() does. If your query has more than one row, +it returns the current row and moves the internal data pointer ahead.

+
$query = $this->db->query("YOUR QUERY");
+
+while ($row = $query->unbuffered_row())
+{
+        echo $row->title;
+        echo $row->name;
+        echo $row->body;
+}
+
+
+

You can optionally pass ‘object’ (default) or ‘array’ in order to specify +the returned value’s type:

+
$query->unbuffered_row();               // object
+$query->unbuffered_row('object');       // object
+$query->unbuffered_row('array');        // associative array
+
+
+
+
+

Custom Result Objects

+

You can have the results returned as an instance of a custom class instead +of a stdClass or array, as the result() and result_array() +methods allow. This requires that the class is already loaded into memory. +The object will have all values returned from the database set as properties. +If these have been declared and are non-public then you should provide a +__set() method to allow them to be set.

+

Example:

+
class User {
+
+        public $id;
+        public $email;
+        public $username;
+
+        protected $last_login;
+
+        public function last_login($format)
+        {
+                return $this->last_login->format($format);
+        }
+
+        public function __set($name, $value)
+        {
+                if ($name === 'last_login')
+                {
+                        $this->last_login = DateTime::createFromFormat('U', $value);
+                }
+        }
+
+        public function __get($name)
+        {
+                if (isset($this->$name))
+                {
+                        return $this->$name;
+                }
+        }
+}
+
+
+

In addition to the two methods listed below, the following methods also can +take a class name to return the results as: first_row(), last_row(), +next_row(), and previous_row().

+

custom_result_object()

+

Returns the entire result set as an array of instances of the class requested. +The only parameter is the name of the class to instantiate.

+

Example:

+
$query = $this->db->query("YOUR QUERY");
+
+$rows = $query->custom_result_object('User');
+
+foreach ($rows as $row)
+{
+        echo $row->id;
+        echo $row->email;
+        echo $row->last_login('Y-m-d');
+}
+
+
+

custom_row_object()

+

Returns a single row from your query results. The first parameter is the row +number of the results. The second parameter is the class name to instantiate.

+

Example:

+
$query = $this->db->query("YOUR QUERY");
+
+$row = $query->custom_row_object(0, 'User');
+
+if (isset($row))
+{
+        echo $row->email;   // access attributes
+        echo $row->last_login('Y-m-d');   // access class methods
+}
+
+
+

You can also use the row() method in exactly the same way.

+

Example:

+
$row = $query->custom_row_object(0, 'User');
+
+
+
+
+

Result Helper Methods

+

num_rows()

+

The number of rows returned by the query. Note: In this example, $query +is the variable that the query result object is assigned to:

+
$query = $this->db->query('SELECT * FROM my_table');
+
+echo $query->num_rows();
+
+
+
+

Note

+

Not all database drivers have a native way of getting the total +number of rows for a result set. When this is the case, all of +the data is prefetched and count() is manually called on the +resulting array in order to achieve the same result.

+
+

num_fields()

+

The number of FIELDS (columns) returned by the query. Make sure to call +the method using your query result object:

+
$query = $this->db->query('SELECT * FROM my_table');
+
+echo $query->num_fields();
+
+
+

free_result()

+

It frees the memory associated with the result and deletes the result +resource ID. Normally PHP frees its memory automatically at the end of +script execution. However, if you are running a lot of queries in a +particular script you might want to free the result after each query +result has been generated in order to cut down on memory consumption.

+

Example:

+
$query = $this->db->query('SELECT title FROM my_table');
+
+foreach ($query->result() as $row)
+{
+        echo $row->title;
+}
+
+$query->free_result();  // The $query result object will no longer be available
+
+$query2 = $this->db->query('SELECT name FROM some_table');
+
+$row = $query2->row();
+echo $row->name;
+$query2->free_result(); // The $query2 result object will no longer be available
+
+
+

data_seek()

+

This method sets the internal pointer for the next result row to be +fetched. It is only useful in combination with unbuffered_row().

+

It accepts a positive integer value, which defaults to 0 and returns +TRUE on success or FALSE on failure.

+
$query = $this->db->query('SELECT `field_name` FROM `table_name`');
+$query->data_seek(5); // Skip the first 5 rows
+$row = $query->unbuffered_row();
+
+
+
+

Note

+

Not all database drivers support this feature and will return FALSE. +Most notably - you won’t be able to use it with PDO.

+
+
+
+

Class Reference

+
+
+class CI_DB_result
+
+
+result([$type = 'object'])
+
+++ + + + + + + + +
Parameters:
    +
  • $type (string) – Type of requested results - array, object, or class name
    • +
+
Returns:

Array containing the fetched rows

+
Return type:

array

+
+

A wrapper for the result_array(), result_object() +and custom_result_object() methods.

+

Usage: see Result Arrays.

+
+ +
+
+result_array()
+
+++ + + + + + +
Returns:Array containing the fetched rows
Return type:array
+

Returns the query results as an array of rows, where each +row is itself an associative array.

+

Usage: see Result Arrays.

+
+ +
+
+result_object()
+
+++ + + + + + +
Returns:Array containing the fetched rows
Return type:array
+

Returns the query results as an array of rows, where each +row is an object of type stdClass.

+

Usage: see Result Arrays.

+
+ +
+
+custom_result_object($class_name)
+
+++ + + + + + + + +
Parameters:
    +
  • $class_name (string) – Class name for the resulting rows
    • +
+
Returns:

Array containing the fetched rows

+
Return type:

array

+
+

Returns the query results as an array of rows, where each +row is an instance of the specified class.

+
+ +
+
+row([$n = 0[, $type = 'object']])
+
+++ + + + + + + + +
Parameters:
    +
  • $n (int) – Index of the query results row to be returned
    • +
  • $type (string) – Type of the requested result - array, object, or class name
    • +
+
Returns:

The requested row or NULL if it doesn’t exist

+
Return type:

mixed

+
+

A wrapper for the row_array(), row_object() and +``custom_row_object() methods.

+

Usage: see Result Rows.

+
+ +
+
+unbuffered_row([$type = 'object'])
+
+++ + + + + + + + +
Parameters:
    +
  • $type (string) – Type of the requested result - array, object, or class name
    • +
+
Returns:

Next row from the result set or NULL if it doesn’t exist

+
Return type:

mixed

+
+

Fetches the next result row and returns it in the +requested form.

+

Usage: see Result Rows.

+
+ +
+
+row_array([$n = 0])
+
+++ + + + + + + + +
Parameters:
    +
  • $n (int) – Index of the query results row to be returned
    • +
+
Returns:

The requested row or NULL if it doesn’t exist

+
Return type:

array

+
+

Returns the requested result row as an associative array.

+

Usage: see Result Rows.

+
+ +
+
+row_object([$n = 0])
+
+++ + + + + + + + +
Parameters:
    +
  • $n (int) – Index of the query results row to be returned
    • +
+
Returns:

The requested row or NULL if it doesn’t exist

+
Return type:

stdClass

+
+

Returns the requested result row as an object of type +stdClass.

+

Usage: see Result Rows.

+
+ +
+
+custom_row_object($n, $type)
+
+++ + + + + + + + +
Parameters:
    +
  • $n (int) – Index of the results row to return
    • +
  • $class_name (string) – Class name for the resulting row
    • +
+
Returns:

The requested row or NULL if it doesn’t exist

+
Return type:

$type

+
+

Returns the requested result row as an instance of the +requested class.

+
+ +
+
+data_seek([$n = 0])
+
+++ + + + + + + + +
Parameters:
    +
  • $n (int) – Index of the results row to be returned next
    • +
+
Returns:

TRUE on success, FALSE on failure

+
Return type:

bool

+
+

Moves the internal results row pointer to the desired offset.

+

Usage: see Result Helper Methods.

+
+ +
+
+set_row($key[, $value = NULL])
+
+++ + + + + + +
Parameters:
    +
  • $key (mixed) – Column name or array of key/value pairs
    • +
  • $value (mixed) – Value to assign to the column, $key is a single field name
    • +
+
Return type:

void

+
+

Assigns a value to a particular column.

+
+ +
+
+next_row([$type = 'object'])
+
+++ + + + + + + + +
Parameters:
    +
  • $type (string) – Type of the requested result - array, object, or class name
    • +
+
Returns:

Next row of result set, or NULL if it doesn’t exist

+
Return type:

mixed

+
+

Returns the next row from the result set.

+
+ +
+
+previous_row([$type = 'object'])
+
+++ + + + + + + + +
Parameters:
    +
  • $type (string) – Type of the requested result - array, object, or class name
    • +
+
Returns:

Previous row of result set, or NULL if it doesn’t exist

+
Return type:

mixed

+
+

Returns the previous row from the result set.

+
+ +
+
+first_row([$type = 'object'])
+
+++ + + + + + + + +
Parameters:
    +
  • $type (string) – Type of the requested result - array, object, or class name
    • +
+
Returns:

First row of result set, or NULL if it doesn’t exist

+
Return type:

mixed

+
+

Returns the first row from the result set.

+
+ +
+
+last_row([$type = 'object'])
+
+++ + + + + + + + +
Parameters:
    +
  • $type (string) – Type of the requested result - array, object, or class name
    • +
+
Returns:

Last row of result set, or NULL if it doesn’t exist

+
Return type:

mixed

+
+

Returns the last row from the result set.

+
+ +
+
+num_rows()
+
+++ + + + + + +
Returns:Number of rows in the result set
Return type:int
+

Returns the number of rows in the result set.

+

Usage: see Result Helper Methods.

+
+ +
+
+num_fields()
+
+++ + + + + + +
Returns:Number of fields in the result set
Return type:int
+

Returns the number of fields in the result set.

+

Usage: see Result Helper Methods.

+
+ +
+
+field_data()
+
+++ + + + + + +
Returns:Array containing field meta-data
Return type:array
+

Generates an array of stdClass objects containing +field meta-data.

+
+ +
+
+free_result()
+
+++ + + + +
Return type:void
+

Frees a result set.

+

Usage: see Result Helper Methods.

+
+ +
+
+list_fields()
+
+++ + + + + + +
Returns:Array of column names
Return type:array
+

Returns an array containing the field names in the +result set.

+
+ +
+ +
+
+ + +
+
+ + + + +
+ +
+

+ © Copyright 2014 - 2018, British Columbia Institute of Technology. + Last updated on Mar 22, 2018. +

+
+ + Built with Sphinx using a theme provided by Read the Docs. + +
+
+
+ +
+ +
+ + + + + + + + + + + + + + + + + + + + + + + + \ No newline at end of file diff --git a/user_guide/database/transactions.html b/user_guide/database/transactions.html new file mode 100644 index 000000000..dff9aac6b --- /dev/null +++ b/user_guide/database/transactions.html @@ -0,0 +1,615 @@ + + + + + + + + + + Transactions — CodeIgniter 3.1.8 documentation + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +
+ + + + +
+ + + + + + +
+
+
+ +
+
+
+ +
+

Transactions

+

CodeIgniter’s database abstraction allows you to use transactions with +databases that support transaction-safe table types. In MySQL, you’ll +need to be running InnoDB or BDB table types rather than the more common +MyISAM. Most other database platforms support transactions natively.

+

If you are not familiar with transactions we recommend you find a good +online resource to learn about them for your particular database. The +information below assumes you have a basic understanding of +transactions.

+
+

CodeIgniter’s Approach to Transactions

+

CodeIgniter utilizes an approach to transactions that is very similar to +the process used by the popular database class ADODB. We’ve chosen that +approach because it greatly simplifies the process of running +transactions. In most cases all that is required are two lines of code.

+

Traditionally, transactions have required a fair amount of work to +implement since they demand that you keep track of your queries and +determine whether to commit or rollback based on the success or failure +of your queries. This is particularly cumbersome with nested queries. In +contrast, we’ve implemented a smart transaction system that does all +this for you automatically (you can also manage your transactions +manually if you choose to, but there’s really no benefit).

+
+
+

Running Transactions

+

To run your queries using transactions you will use the +$this->db->trans_start() and $this->db->trans_complete() functions as +follows:

+
$this->db->trans_start();
+$this->db->query('AN SQL QUERY...');
+$this->db->query('ANOTHER QUERY...');
+$this->db->query('AND YET ANOTHER QUERY...');
+$this->db->trans_complete();
+
+
+

You can run as many queries as you want between the start/complete +functions and they will all be committed or rolled back based on success +or failure of any given query.

+
+
+

Strict Mode

+

By default CodeIgniter runs all transactions in Strict Mode. When strict +mode is enabled, if you are running multiple groups of transactions, if +one group fails all groups will be rolled back. If strict mode is +disabled, each group is treated independently, meaning a failure of one +group will not affect any others.

+

Strict Mode can be disabled as follows:

+
$this->db->trans_strict(FALSE);
+
+
+
+
+

Managing Errors

+

If you have error reporting enabled in your config/database.php file +you’ll see a standard error message if the commit was unsuccessful. If +debugging is turned off, you can manage your own errors like this:

+
$this->db->trans_start();
+$this->db->query('AN SQL QUERY...');
+$this->db->query('ANOTHER QUERY...');
+$this->db->trans_complete();
+
+if ($this->db->trans_status() === FALSE)
+{
+        // generate an error... or use the log_message() function to log your error
+}
+
+
+
+
+

Disabling Transactions

+

If you would like to disable transactions you can do so using +$this->db->trans_off():

+
$this->db->trans_off();
+
+$this->db->trans_start();
+$this->db->query('AN SQL QUERY...');
+$this->db->trans_complete();
+
+
+

When transactions are disabled, your queries will be auto-committed, just as +they are when running queries without transactions, practically ignoring +any calls to trans_start(), trans_complete(), etc.

+
+
+

Test Mode

+

You can optionally put the transaction system into “test mode”, which +will cause your queries to be rolled back – even if the queries produce +a valid result. To use test mode simply set the first parameter in the +$this->db->trans_start() function to TRUE:

+
$this->db->trans_start(TRUE); // Query will be rolled back
+$this->db->query('AN SQL QUERY...');
+$this->db->trans_complete();
+
+
+
+
+

Running Transactions Manually

+

If you would like to run transactions manually you can do so as follows:

+
$this->db->trans_begin();
+
+$this->db->query('AN SQL QUERY...');
+$this->db->query('ANOTHER QUERY...');
+$this->db->query('AND YET ANOTHER QUERY...');
+
+if ($this->db->trans_status() === FALSE)
+{
+        $this->db->trans_rollback();
+}
+else
+{
+        $this->db->trans_commit();
+}
+
+
+
+

Note

+

Make sure to use $this->db->trans_begin() when running manual +transactions, NOT $this->db->trans_start().

+
+
+
+ + +
+
+ + + + +
+ +
+

+ © Copyright 2014 - 2018, British Columbia Institute of Technology. + Last updated on Mar 22, 2018. +

+
+ + Built with Sphinx using a theme provided by Read the Docs. + +
+
+
+ +
+ +
+ + + + + + + + + + + + + + + + + + + + + + + + \ No newline at end of file diff --git a/user_guide/database/utilities.html b/user_guide/database/utilities.html new file mode 100644 index 000000000..44b5590a5 --- /dev/null +++ b/user_guide/database/utilities.html @@ -0,0 +1,993 @@ + + + + + + + + + + Database Utility Class — CodeIgniter 3.1.8 documentation + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +
+ + + + +
+ + + + + + +
+
+
+ +
+
+
+ +
+

Database Utility Class

+

The Database Utility Class contains methods that help you manage your +database.

+ +
+

Initializing the Utility Class

+
+

Important

+

In order to initialize the Utility class, your database +driver must already be running, since the utilities class relies on it.

+
+

Load the Utility Class as follows:

+
$this->load->dbutil();
+
+
+

You can also pass another database object to the DB Utility loader, in case +the database you want to manage isn’t the default one:

+
$this->myutil = $this->load->dbutil($this->other_db, TRUE);
+
+
+

In the above example, we’re passing a custom database object as the first +parameter and then tell it to return the dbutil object, instead of +assigning it directly to $this->dbutil.

+
+

Note

+

Both of the parameters can be used individually, just pass an empty +value as the first one if you wish to skip it.

+
+

Once initialized you will access the methods using the $this->dbutil +object:

+
$this->dbutil->some_method();
+
+
+
+
+

Using the Database Utilities

+
+

Retrieve list of database names

+

Returns an array of database names:

+
$dbs = $this->dbutil->list_databases();
+
+foreach ($dbs as $db)
+{
+        echo $db;
+}
+
+
+
+
+

Determine If a Database Exists

+

Sometimes it’s helpful to know whether a particular database exists. +Returns a boolean TRUE/FALSE. Usage example:

+
if ($this->dbutil->database_exists('database_name'))
+{
+        // some code...
+}
+
+
+
+

Note

+

Replace database_name with the name of the database you are +looking for. This method is case sensitive.

+
+
+
+

Optimize a Table

+

Permits you to optimize a table using the table name specified in the +first parameter. Returns TRUE/FALSE based on success or failure:

+
if ($this->dbutil->optimize_table('table_name'))
+{
+        echo 'Success!';
+}
+
+
+
+

Note

+

Not all database platforms support table optimization. It is +mostly for use with MySQL.

+
+
+
+

Repair a Table

+

Permits you to repair a table using the table name specified in the +first parameter. Returns TRUE/FALSE based on success or failure:

+
if ($this->dbutil->repair_table('table_name'))
+{
+        echo 'Success!';
+}
+
+
+
+

Note

+

Not all database platforms support table repairs.

+
+
+
+

Optimize a Database

+

Permits you to optimize the database your DB class is currently +connected to. Returns an array containing the DB status messages or +FALSE on failure.

+
$result = $this->dbutil->optimize_database();
+
+if ($result !== FALSE)
+{
+        print_r($result);
+}
+
+
+
+

Note

+

Not all database platforms support database optimization. It +it is mostly for use with MySQL.

+
+
+
+

Export a Query Result as a CSV File

+

Permits you to generate a CSV file from a query result. The first +parameter of the method must contain the result object from your +query. Example:

+
$this->load->dbutil();
+
+$query = $this->db->query("SELECT * FROM mytable");
+
+echo $this->dbutil->csv_from_result($query);
+
+
+

The second, third, and fourth parameters allow you to set the delimiter +newline, and enclosure characters respectively. By default commas are +used as the delimiter, “n” is used as a new line, and a double-quote +is used as the enclosure. Example:

+
$delimiter = ",";
+$newline = "\r\n";
+$enclosure = '"';
+
+echo $this->dbutil->csv_from_result($query, $delimiter, $newline, $enclosure);
+
+
+
+

Important

+

This method will NOT write the CSV file for you. It +simply creates the CSV layout. If you need to write the file +use the File Helper.

+
+
+
+

Export a Query Result as an XML Document

+

Permits you to generate an XML file from a query result. The first +parameter expects a query result object, the second may contain an +optional array of config parameters. Example:

+
$this->load->dbutil();
+
+$query = $this->db->query("SELECT * FROM mytable");
+
+$config = array (
+        'root'          => 'root',
+        'element'       => 'element',
+        'newline'       => "\n",
+        'tab'           => "\t"
+);
+
+echo $this->dbutil->xml_from_result($query, $config);
+
+
+
+

Important

+

This method will NOT write the XML file for you. It +simply creates the XML layout. If you need to write the file +use the File Helper.

+
+
+
+
+

Backup Your Database

+
+

Database Backup Notes

+

Permits you to backup your full database or individual tables. The +backup data can be compressed in either Zip or Gzip format.

+
+

Note

+

This feature is only available for MySQL and Interbase/Firebird databases.

+
+
+

Note

+

For Interbase/Firebird databases, the backup file name is the only parameter.

+

$this->dbutil->backup(‘db_backup_filename’);

+
+
+

Note

+

Due to the limited execution time and memory available to PHP, +backing up very large databases may not be possible. If your database is +very large you might need to backup directly from your SQL server via +the command line, or have your server admin do it for you if you do not +have root privileges.

+
+
+
+

Usage Example

+
// Load the DB utility class
+$this->load->dbutil();
+
+// Backup your entire database and assign it to a variable
+$backup = $this->dbutil->backup();
+
+// Load the file helper and write the file to your server
+$this->load->helper('file');
+write_file('/path/to/mybackup.gz', $backup);
+
+// Load the download helper and send the file to your desktop
+$this->load->helper('download');
+force_download('mybackup.gz', $backup);
+
+
+
+
+

Setting Backup Preferences

+

Backup preferences are set by submitting an array of values to the first +parameter of the backup() method. Example:

+
$prefs = array(
+        'tables'        => array('table1', 'table2'),   // Array of tables to backup.
+        'ignore'        => array(),                     // List of tables to omit from the backup
+        'format'        => 'txt',                       // gzip, zip, txt
+        'filename'      => 'mybackup.sql',              // File name - NEEDED ONLY WITH ZIP FILES
+        'add_drop'      => TRUE,                        // Whether to add DROP TABLE statements to backup file
+        'add_insert'    => TRUE,                        // Whether to add INSERT data to backup file
+        'newline'       => "\n"                         // Newline character used in backup file
+);
+
+$this->dbutil->backup($prefs);
+
+
+
+
+

Description of Backup Preferences

+ ++++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +
PreferenceDefault ValueOptionsDescription
tablesempty arrayNoneAn array of tables you want backed up. If left blank all tables will be +exported.
ignoreempty arrayNoneAn array of tables you want the backup routine to ignore.
formatgzipgzip, zip, txtThe file format of the export file.
filenamethe current date/timeNoneThe name of the backed-up file. The name is needed only if you are using +zip compression.
add_dropTRUETRUE/FALSEWhether to include DROP TABLE statements in your SQL export file.
add_insertTRUETRUE/FALSEWhether to include INSERT statements in your SQL export file.
newline“\n”“\n”, “\r”, “\r\n”Type of newline to use in your SQL export file.
foreign_key_checksTRUETRUE/FALSEWhether output should keep foreign key checks enabled.
+
+
+
+

Class Reference

+
+
+class CI_DB_utility
+
+
+backup([$params = array()])
+
+++ + + + + + + + +
Parameters:
    +
  • $params (array) – An associative array of options
    • +
+
Returns:

raw/(g)zipped SQL query string

+
Return type:

string

+
+

Perform a database backup, per user preferences.

+
+ +
+
+database_exists($database_name)
+
+++ + + + + + + + +
Parameters:
    +
  • $database_name (string) – Database name
    • +
+
Returns:

TRUE if the database exists, FALSE otherwise

+
Return type:

bool

+
+

Check for the existence of a database.

+
+ +
+
+list_databases()
+
+++ + + + + + +
Returns:Array of database names found
Return type:array
+

Retrieve a list of all the database names.

+
+ +
+
+optimize_database()
+
+++ + + + + + +
Returns:Array of optimization messages or FALSE on failure
Return type:array
+

Optimizes the database.

+
+ +
+
+optimize_table($table_name)
+
+++ + + + + + + + +
Parameters:
    +
  • $table_name (string) – Name of the table to optimize
    • +
+
Returns:

Array of optimization messages or FALSE on failure

+
Return type:

array

+
+

Optimizes a database table.

+
+ +
+
+repair_table($table_name)
+
+++ + + + + + + + +
Parameters:
    +
  • $table_name (string) – Name of the table to repair
    • +
+
Returns:

Array of repair messages or FALSE on failure

+
Return type:

array

+
+

Repairs a database table.

+
+ +
+
+csv_from_result($query[, $delim = ', '[, $newline = "n"[, $enclosure = '"']]])
+
+++ + + + + + + + +
Parameters:
    +
  • $query (object) – A database result object
    • +
  • $delim (string) – The CSV field delimiter to use
    • +
  • $newline (string) – The newline character to use
    • +
  • $enclosure (string) – The enclosure delimiter to use
    • +
+
Returns:

The generated CSV file as a string

+
Return type:

string

+
+

Translates a database result object into a CSV document.

+
+ +
+
+xml_from_result($query[, $params = array()])
+
+++ + + + + + + + +
Parameters:
    +
  • $query (object) – A database result object
    • +
  • $params (array) – An associative array of preferences
    • +
+
Returns:

The generated XML document as a string

+
Return type:

string

+
+

Translates a database result object into an XML document.

+
+ +
+ +
+
+ + +
+
+ + + + +
+ +
+

+ © Copyright 2014 - 2018, British Columbia Institute of Technology. + Last updated on Mar 22, 2018. +

+
+ + Built with Sphinx using a theme provided by Read the Docs. + +
+
+
+ +
+ +
+ + + + + + + + + + + + + + + + + + + + + + + + \ No newline at end of file -- cgit v1.2.3-24-g4f1b