diff options
Diffstat (limited to 'user_guide_src/source/database')
| -rw-r--r-- | user_guide_src/source/database/configuration.rst | 3 | ||||
| -rw-r--r-- | user_guide_src/source/database/forge.rst | 136 | ||||
| -rw-r--r-- | user_guide_src/source/database/helpers.rst | 61 | ||||
| -rw-r--r-- | user_guide_src/source/database/index.rst | 5 | ||||
| -rw-r--r-- | user_guide_src/source/database/metadata.rst (renamed from user_guide_src/source/database/fields.rst) | 70 | ||||
| -rw-r--r-- | user_guide_src/source/database/queries.rst | 24 | ||||
| -rw-r--r-- | user_guide_src/source/database/query_builder.rst | 230 | ||||
| -rw-r--r-- | user_guide_src/source/database/results.rst | 43 | ||||
| -rw-r--r-- | user_guide_src/source/database/table_data.rst | 31 | ||||
| -rw-r--r-- | user_guide_src/source/database/utilities.rst | 131 |
10 files changed, 514 insertions, 220 deletions
diff --git a/user_guide_src/source/database/configuration.rst b/user_guide_src/source/database/configuration.rst index 34cefffbd..9f52ad2a2 100644 --- a/user_guide_src/source/database/configuration.rst +++ b/user_guide_src/source/database/configuration.rst @@ -141,7 +141,8 @@ Query Builder The :doc:`Query Builder Class <query_builder>` is globally enabled or disabled by setting the $query_builder variable in the database -configuration file to TRUE/FALSE (boolean). If you are not using the +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. diff --git a/user_guide_src/source/database/forge.rst b/user_guide_src/source/database/forge.rst index 48642ad7e..59a6591b7 100644 --- a/user_guide_src/source/database/forge.rst +++ b/user_guide_src/source/database/forge.rst @@ -6,6 +6,7 @@ The Database Forge Class contains methods that help you manage your database. .. contents:: Table of Contents + :depth: 3 **************************** Initializing the Forge Class @@ -35,8 +36,11 @@ object:: $this->dbforge->some_method(); -$this->dbforge->create_database('db_name') -========================================== +******************************* +Creating and Dropping Databases +******************************* + +**$this->dbforge->create_database('db_name')** Permits you to create the database specified in the first parameter. Returns TRUE/FALSE based on success or failure:: @@ -46,8 +50,7 @@ Returns TRUE/FALSE based on success or failure:: echo 'Database created!'; } -$this->dbforge->drop_database('db_name') -========================================== +**$this->dbforge->drop_database('db_name')** Permits you to drop the database specified in the first parameter. Returns TRUE/FALSE based on success or failure:: @@ -57,6 +60,7 @@ Returns TRUE/FALSE based on success or failure:: echo 'Database deleted!'; } + **************************** Creating and Dropping Tables **************************** @@ -123,11 +127,11 @@ After the fields have been defined, they can be added using ``$this->dbforge->add_field($fields);`` followed by a call to the ``create_table()`` method. -$this->dbforge->add_field() ---------------------------- +**$this->dbforge->add_field()** The add fields method will accept the above array. + Passing strings as fields ------------------------- @@ -211,6 +215,7 @@ You could also pass optional table attributes, such as MySQL's ``ENGINE``:: ``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 ================ @@ -224,6 +229,7 @@ Execute a DROP TABLE statement and optionally add an IF EXISTS clause. // Produces: DROP TABLE IF EXISTS table_name $this->dbforge->drop_table('table_name'); + Renaming a table ================ @@ -239,8 +245,10 @@ Executes a TABLE rename Modifying Tables **************** -$this->dbforge->add_column() -============================ +Adding a Column to a Table +========================== + +**$this->dbforge->add_column()** The ``add_column()`` method is used to modify an existing table. It accepts the same field array as above, and can be used for an unlimited @@ -269,8 +277,11 @@ Examples:: 'preferences' => array('type' => 'TEXT', 'first' => TRUE) ); -$this->dbforge->drop_column() -============================= + +Dropping a Column From a Table +============================== + +**$this->dbforge->drop_column()** Used to remove a column from a table. @@ -279,8 +290,11 @@ Used to remove a column from a table. $this->dbforge->drop_column('table_name', 'column_to_drop'); -$this->dbforge->modify_column() -=============================== + +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 @@ -295,4 +309,100 @@ change the name you can add a "name" key into the field defining array. ), ); $this->dbforge->modify_column('table_name', $fields); - // gives ALTER TABLE table_name CHANGE old_name new_name TEXT
\ No newline at end of file + // gives ALTER TABLE table_name CHANGE old_name new_name TEXT + + +*************** +Class Reference +*************** + +.. class:: CI_DB_forge + + .. method:: add_column($table[, $field = array()[, $_after = NULL]]) + + :param string $table: Table name to add the column to + :param array $field: Column definition(s) + :param string $_after: Column for AFTER clause (deprecated) + :returns: TRUE on success, FALSE on failure + :rtype: bool + + Adds a column to a table. Usage: See `Adding a Column to a Table`_. + + .. method:: add_field($field) + + :param array $field: Field definition to add + :returns: CI_DB_forge instance (method chaining) + :rtype: CI_DB_forge + + Adds a field to the set that will be used to create a table. Usage: See `Adding fields`_. + + .. method:: add_key($key[, $primary = FALSE]) + + :param array $key: Name of a key field + :param bool $primary: Set to TRUE if it should be a primary key or a regular one + :returns: CI_DB_forge instance (method chaining) + :rtype: CI_DB_forge + + Adds a key to the set that will be used to create a table. Usage: See `Adding Keys`_. + + .. method:: create_database($db_name) + + :param string $db_name: Name of the database to create + :returns: TRUE on success, FALSE on failure + :rtype: bool + + Creates a new database. Usage: See `Creating and Dropping Databases`_. + + .. method:: create_table($table[, $if_not_exists = FALSE[, array $attributes = array()]]) + + :param string $table: Name of the table to create + :param string $if_not_exists: Set to TRUE to add an 'IF NOT EXISTS' clause + :param string $attributes: An associative array of table attributes + :returns: TRUE on success, FALSE on failure + :rtype: bool + + Creates a new table. Usage: See `Creating a table`_. + + .. method:: drop_column($table, $column_name) + + :param string $table: Table name + :param array $column_name: The column name to drop + :returns: TRUE on success, FALSE on failure + :rtype: bool + + Drops a column from a table. Usage: See `Dropping a Column From a Table`_. + + .. method:: drop_database($db_name) + + :param string $db_name: Name of the database to drop + :returns: TRUE on success, FALSE on failure + :rtype: bool + + Drops a database. Usage: See `Creating and Dropping Databases`_. + + .. method:: drop_table($table_name[, $if_exists = FALSE]) + + :param string $table: Name of the table to drop + :param string $if_exists: Set to TRUE to add an 'IF EXISTS' clause + :returns: TRUE on success, FALSE on failure + :rtype: bool + + Drops a table. Usage: See `Dropping a table`_. + + .. method:: modify_column($table, $field) + + :param string $table: Table name + :param array $field: Column definition(s) + :returns: TRUE on success, FALSE on failure + :rtype: bool + + Modifies a table column. Usage: See `Modifying a Column in a Table`_. + + .. method:: rename_table($table_name, $new_table_name) + + :param string $table: Current of the table + :param string $new_table_name: New name of the table + :returns: TRUE on success, FALSE on failure + :rtype: bool + + Renames a table. Usage: See `Renaming a table`_.
\ No newline at end of file diff --git a/user_guide_src/source/database/helpers.rst b/user_guide_src/source/database/helpers.rst index 77bf1b5d2..2d997a9e0 100644 --- a/user_guide_src/source/database/helpers.rst +++ b/user_guide_src/source/database/helpers.rst @@ -1,9 +1,11 @@ -###################### -Query Helper Functions -###################### +#################### +Query Helper Methods +#################### -$this->db->insert_id() -====================== +Information From Executing a Query +================================== + +**$this->db->insert_id()** The insert ID number when performing database inserts. @@ -11,8 +13,7 @@ The insert ID number when performing database inserts. driver, this function requires a $name parameter, which specifies the appropriate sequence to check for the insert id. -$this->db->affected_rows() -========================== +**$this->db->affected_rows()** Displays the number of affected rows, when doing "write" type queries (insert, update, etc.). @@ -22,8 +23,23 @@ Displays the number of affected rows, when doing "write" type queries affected rows. By default this hack is enabled but it can be turned off in the database driver file. -$this->db->count_all() -====================== +**$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:: @@ -32,38 +48,24 @@ Submit the table name in the first parameter. Example:: // Produces an integer, like 25 -$this->db->platform() -===================== +**$this->db->platform()** Outputs the database platform you are running (MySQL, MS SQL, Postgres, etc...):: echo $this->db->platform(); -$this->db->version() -==================== +**$this->db->version()** Outputs the database version you are running:: echo $this->db->version(); -$this->db->last_query() -======================= - -Returns the last query that was run (the query string, not the result). -Example:: - - $str = $this->db->last_query(); - - // Produces: SELECT * FROM sometable.... - - -.. note:: Disabling the **save_queries** setting in your database - configuration will render this function useless. - -$this->db->insert_string() +Making Your Queries Easier ========================== +**$this->db->insert_string()** + This function simplifies the process of writing database inserts. It returns a correctly formatted SQL insert string. Example:: @@ -78,8 +80,7 @@ array with the data to be inserted. The above example produces:: .. note:: Values are automatically escaped, producing safer queries. -$this->db->update_string() -========================== +**$this->db->update_string()** This function simplifies the process of writing database updates. It returns a correctly formatted SQL update string. Example:: diff --git a/user_guide_src/source/database/index.rst b/user_guide_src/source/database/index.rst index 7ccb8fb00..4612daf9d 100644 --- a/user_guide_src/source/database/index.rst +++ b/user_guide_src/source/database/index.rst @@ -1,5 +1,5 @@ ################## -The Database Class +Database Reference ################## CodeIgniter comes with a full-featured and very fast abstracted database @@ -17,8 +17,7 @@ patterns. The database functions offer clear, simple syntax. Query Helper Functions <helpers> Query Builder Class <query_builder> Transactions <transactions> - Table MetaData <table_data> - Field MetaData <fields> + Getting MetaData <metadata> Custom Function Calls <call_function> Query Caching <caching> Database Manipulation with Database Forge <forge> diff --git a/user_guide_src/source/database/fields.rst b/user_guide_src/source/database/metadata.rst index b706ace7d..b8be809b6 100644 --- a/user_guide_src/source/database/fields.rst +++ b/user_guide_src/source/database/metadata.rst @@ -1,9 +1,53 @@ -########## -Field Data -########## +################# +Database Metadata +################# -$this->db->list_fields() -========================= +************** +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: @@ -28,8 +72,11 @@ calling the function from your query result object:: echo $field; } -$this->db->field_exists() -========================== + +Determine If a Field is Present in a Table +========================================== + +**$this->db->field_exists()** Sometimes it's helpful to know whether a particular field exists before performing an action. Returns a boolean TRUE/FALSE. Usage example:: @@ -43,8 +90,11 @@ performing an action. Returns a boolean TRUE/FALSE. Usage example:: for, and replace *table_name* with the name of the table you are looking for. -$this->db->field_data() -======================== + +Retrieve Field Metadata +======================= + +**$this->db->field_data()** Returns an array of objects containing field information. @@ -77,4 +127,4 @@ database: - name - column name - max_length - maximum length of the column - primary_key - 1 if the column is a primary key -- type - the type of the column
\ No newline at end of file +- type - the type of the column diff --git a/user_guide_src/source/database/queries.rst b/user_guide_src/source/database/queries.rst index 76ff1083f..43a0a30bf 100644 --- a/user_guide_src/source/database/queries.rst +++ b/user_guide_src/source/database/queries.rst @@ -2,10 +2,14 @@ Queries ####### -$this->db->query(); -=================== +************ +Query Basics +************ -To submit a query, use the following function:: +Regular Queries +=============== + +To submit a query, use the **query** function:: $this->db->query('YOUR QUERY HERE'); @@ -18,10 +22,11 @@ this:: $query = $this->db->query('YOUR QUERY HERE'); -$this->db->simple_query(); -========================== +Simplified Queries +================== -This is a simplified version of the $this->db->query() method. It DOES +The **simple_query** method is a simplified version of the +$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. @@ -116,7 +121,9 @@ this: :: - $search = '20% raise'; $sql = "SELECT id FROM table WHERE column LIKE '%".$this->db->escape_like_str($search)."%'"; + $search = '20% raise'; + $sql = "SELECT id FROM table WHERE column LIKE '%" . + $this->db->escape_like_str($search)."%'"; ************** @@ -150,8 +157,7 @@ you. Handling Errors *************** -$this->db->error(); -=================== +**$this->db->error();** If you need to get the last error that has occured, the error() method will return an array containing its code and message. Here's a quick diff --git a/user_guide_src/source/database/query_builder.rst b/user_guide_src/source/database/query_builder.rst index 5bfdfdb52..3203ff103 100644 --- a/user_guide_src/source/database/query_builder.rst +++ b/user_guide_src/source/database/query_builder.rst @@ -19,7 +19,9 @@ system. class in your database config file, allowing the core database library and adapter to utilize fewer resources. -.. contents:: Page Contents +.. contents:: + :local: + :depth: 1 ************** Selecting Data @@ -28,7 +30,7 @@ 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:: @@ -39,7 +41,8 @@ The second and third parameters enable you to set a limit and offset clause:: $query = $this->db->get('mytable', 10, 20); - // Produces: SELECT * FROM mytable LIMIT 20, 10 (in MySQL. Other databases have slightly different syntax) + // Produces: 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:: @@ -54,10 +57,13 @@ $query, which can be used to show the results:: Please visit the :doc:`result functions <results>` page for a full discussion regarding result generation. +:returns: DB_Result for a successful "read", + TRUE for a successful "write", FALSE if an error + $this->db->get_compiled_select() -================================ +-------------------------------- -Compiles the selection query just like `$this->db->get()`_ but does not *run* +Compiles the selection query just like **$this->db->get()** but does not *run* the query. This method simply returns the SQL query as a string. Example:: @@ -79,14 +85,15 @@ will be reset (by default it will be reset, just like when using `$this->db->get // Produces 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 `$this->db->from()`_ and did not pass a table name into the first +utilize **$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()`_. +executed using **$this->db->get()** which resets values or reset directly +using **$this->db->reset_query()**. +:returns: The SQL select string $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() @@ -98,8 +105,11 @@ Please read the about the where function below for more information. .. note:: get_where() was formerly known as getwhere(), which has been removed +:returns: DB_Result for a successful "read", + TRUE for a successful "write", FALSE if an error + $this->db->select() -=================== +------------------- Permits you to write the SELECT portion of your query:: @@ -119,9 +129,10 @@ with backticks. This is useful if you need a compound select statement. $this->db->select('(SELECT SUM(payments.amount) FROM payments WHERE payments.invoice_id=4') AS amount_paid', FALSE); $query = $this->db->get('mytable'); +:returns: The query builder object $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. @@ -135,8 +146,7 @@ include a second parameter to rename the resulting field. $query = $this->db->get('members'); // Produces: SELECT MAX(age) as member_age FROM members -$this->db->select_min() -======================= +**$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 @@ -148,8 +158,7 @@ the resulting field. $query = $this->db->get('members'); // Produces: SELECT MIN(age) as age FROM members -$this->db->select_avg() -======================= +**$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 @@ -161,8 +170,7 @@ the resulting field. $query = $this->db->get('members'); // Produces: SELECT AVG(age) as age FROM members -$this->db->select_sum() -======================= +**$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 @@ -173,9 +181,11 @@ the resulting field. $this->db->select_sum('age'); $query = $this->db->get('members'); // Produces: SELECT SUM(age) as age FROM members +:returns: The query builder object + $this->db->from() -================= +----------------- Permits you to write the FROM portion of your query:: @@ -186,8 +196,10 @@ Permits you to write the FROM portion of your query:: .. 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. +:returns: The query builder object + $this->db->join() -================= +----------------- Permits you to write the JOIN portion of your query:: @@ -211,8 +223,14 @@ outer, and right outer. $this->db->join('comments', 'comments.id = blogs.id', 'left'); // Produces: LEFT JOIN comments ON comments.id = blogs.id +:returns: The query builder object + +************************* +Looking for Specific Data +************************* + $this->db->where() -================== +------------------ This function enables you to set **WHERE** clauses using one of four methods: @@ -277,9 +295,7 @@ with backticks. $this->db->where('MATCH (field) AGAINST ("value")', NULL, FALSE); - -$this->db->or_where() -===================== +**$this->db->or_where()** This function is identical to the one above, except that multiple instances are joined by OR:: @@ -290,8 +306,10 @@ instances are joined by OR:: .. note:: or_where() was formerly known as orwhere(), which has been removed. +:returns: The query builder object + $this->db->where_in() -===================== +--------------------- Generates a WHERE field IN ('item', 'item') SQL query joined with AND if appropriate @@ -303,8 +321,7 @@ appropriate // Produces: WHERE username IN ('Frank', 'Todd', 'James') -$this->db->or_where_in() -======================== +**$this->db->or_where_in()** Generates a WHERE field IN ('item', 'item') SQL query joined with OR if appropriate @@ -315,9 +332,10 @@ appropriate $this->db->or_where_in('username', $names); // Produces: OR username IN ('Frank', 'Todd', 'James') +:returns: The query builder object $this->db->where_not_in() -========================= +------------------------- Generates a WHERE field NOT IN ('item', 'item') SQL query joined with AND if appropriate @@ -329,8 +347,7 @@ AND if appropriate // Produces: WHERE username NOT IN ('Frank', 'Todd', 'James') -$this->db->or_where_not_in() -============================ +**$this->db->or_where_not_in()** Generates a WHERE field NOT IN ('item', 'item') SQL query joined with OR if appropriate @@ -341,9 +358,15 @@ if appropriate $this->db->or_where_not_in('username', $names); // Produces: OR username NOT IN ('Frank', 'Todd', 'James') +:returns: The query builder object + + +************************ +Looking for Similar Data +************************ $this->db->like() -================= +----------------- This method enables you to generate **LIKE** clauses, useful for doing searches. @@ -383,8 +406,7 @@ searches. // WHERE `title` LIKE '%match%' ESCAPE '!' AND `page1` LIKE '%match%' ESCAPE '!' AND `page2` LIKE '%match%' ESCAPE '!' -$this->db->or_like() -==================== +**$this->db->or_like()** This method is identical to the one above, except that multiple instances are joined by OR:: @@ -394,16 +416,14 @@ instances are joined by OR:: .. note:: ``or_like()`` was formerly known as ``orlike()``, which has been removed. -$this->db->not_like() -===================== +**$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->db->or_not_like()** This method is identical to ``not_like()``, except that multiple instances are joined by OR:: @@ -412,8 +432,10 @@ instances are joined by OR:: $this->db->or_not_like('body', 'match'); // WHERE `title` LIKE '%match% OR `body` NOT LIKE '%match%' ESCAPE '!' +:returns: The query builder object + $this->db->group_by() -===================== +--------------------- Permits you to write the GROUP BY portion of your query:: @@ -426,8 +448,10 @@ You can also pass an array of multiple values as well:: .. note:: group_by() was formerly known as groupby(), which has been removed. +:returns: The query builder object + $this->db->distinct() -===================== +--------------------- Adds the "DISTINCT" keyword to a query @@ -436,9 +460,10 @@ Adds the "DISTINCT" keyword to a query $this->db->distinct(); $this->db->get('table'); // Produces: SELECT DISTINCT * FROM table +:returns: The query builder object $this->db->having() -=================== +------------------- Permits you to write the HAVING portion of your query. There are 2 possible syntaxes, 1 argument or 2:: @@ -462,13 +487,18 @@ setting it to FALSE. $this->db->having('user_id', 45, FALSE); // Produces: HAVING user_id = 45 -$this->db->or_having() -====================== +**$this->db->or_having()** Identical to having(), only separates multiple clauses with "OR". +:returns: The query builder object + +**************** +Ordering results +**************** + $this->db->order_by() -===================== +--------------------- Lets you set an ORDER BY clause. @@ -512,8 +542,14 @@ be ignored, unless you specify a numeric seed value. .. note:: Random ordering is not currently supported in Oracle and will default to ASC instead. +:returns: The query builder object + +**************************** +Limiting or Counting Results +**************************** + $this->db->limit() -================== +------------------ Lets you limit the number of rows you would like returned by the query:: @@ -525,8 +561,10 @@ 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) +:returns: The query builder object + $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 @@ -537,14 +575,18 @@ where(), or_where(), like(), or_like(), etc. Example:: $this->db->from('my_table'); echo $this->db->count_all_results(); // Produces an integer, like 17 +:returns: Count of all the records returned by a query + $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 $this->db->count_all('my_table'); // Produces an integer, like 25 +:returns: Count of all the records in the specified table + ************** Query grouping ************** @@ -568,37 +610,34 @@ you to create queries with complex WHERE clauses. Nested groups are supported. E .. note:: groups need to be balanced, make sure every group_start() is matched by a group_end(). -$this->db->group_start() -======================== +**$this->db->group_start()** Starts a new group by adding an opening parenthesis to the WHERE clause of the query. -$this->db->or_group_start() -=========================== +**$this->db->or_group_start()** Starts a new group by adding an opening parenthesis to the WHERE clause of the query, prefixing it with 'OR'. -$this->db->not_group_start() -============================ +**$this->db->not_group_start()** Starts a new group by adding an opening parenthesis to the WHERE clause of the query, prefixing it with 'NOT'. -$this->db->or_not_group_start() -=============================== +**$this->db->or_not_group_start()** Starts a new group by adding an opening parenthesis to the WHERE clause of the query, prefixing it with 'OR NOT'. -$this->db->group_end() -====================== +**$this->db->group_end()** Ends the current group by adding an closing parenthesis to the WHERE clause of the query. +:returns: The query builder object + ************** 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 @@ -635,8 +674,11 @@ object. .. note:: All values are escaped automatically producing safer queries. +:returns: DB_Query on success, FALSE on failure + $this->db->get_compiled_insert() -================================ +-------------------------------- + Compiles the insertion query just like `$this->db->insert()`_ but does not *run* the query. This method simply returns the SQL query as a string. @@ -672,8 +714,10 @@ using `$this->db->insert()` which resets values or reset directly using .. note:: This method doesn't work for batched inserts. +:returns: The SQL insert string + $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 @@ -700,8 +744,14 @@ associative array of values. .. note:: All values are escaped automatically producing safer queries. +:returns: Count of the number of records inserted on success, FALSE on failure + +************* +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* @@ -729,8 +779,10 @@ 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()``. +:returns: DB_query object on success, FALSE on failure + $this->db->set() -================ +---------------- This function enables you to set values for inserts or updates. @@ -788,12 +840,10 @@ Or an object:: $this->db->set($object); $this->db->insert('mytable'); -************* -Updating Data -************* +:returns: The query builder object $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 @@ -839,9 +889,10 @@ Or as an array:: You may also use the $this->db->set() function described above when performing updates. +:returns: DB_query object on success, FALSE on failure $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. @@ -882,8 +933,10 @@ array of values, the third parameter is the where key. due to the very nature of how it works. Instead, ``update_batch()`` returns the number of rows affected. +:returns: Count of the number of records affected on success, FALSE on failure + $this->db->get_compiled_update() -================================ +-------------------------------- This works exactly the same way as ``$this->db->get_compiled_insert()`` except that it produces an UPDATE SQL string instead of an INSERT SQL string. @@ -892,12 +945,14 @@ For more information view documentation for `$this->db->get_compiled_insert()`. .. note:: This method doesn't work for batched updates. +:returns: The SQL update string + ************* Deleting Data ************* $this->db->delete() -=================== +------------------- Generates a delete SQL string and runs the query. @@ -930,17 +985,21 @@ delete data from more than 1 table. If you want to delete all data from a table, you can use the truncate() function, or empty_table(). +:returns: DB_Query on success, FALSE on failure + $this->db->empty_table() -======================== +------------------------ Generates a delete SQL string and runs the query.:: $this->db->empty_table('mytable'); // Produces: DELETE FROM mytable +:returns: DB_Query on success, FALSE on failure + $this->db->truncate() -===================== +--------------------- Generates a truncate SQL string and runs the query. @@ -959,13 +1018,20 @@ Generates a truncate SQL string and runs the query. .. note:: If the TRUNCATE command isn't available, truncate() will execute as "DELETE FROM table". +:returns: DB_Query on success, FALSE on failure + $this->db->get_compiled_delete() -================================ +-------------------------------- + This works exactly the same way as ``$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 `$this->db->get_compiled_insert()`_. +:returns: The SQL delete string + + + *************** Method Chaining *************** @@ -994,23 +1060,25 @@ Cached calls are cumulative. If you make 2 cached select() calls, and then 2 uncached select() calls, this will result in 4 select() calls. There are three Caching functions available: -$this->db->start_cache() -======================== +**$this->db->start_cache()** This function must be called to begin caching. All Query Builder queries of the correct type (see below for supported queries) are stored for later use. -$this->db->stop_cache() -======================= +**$this->db->stop_cache()** This function can be called to stop caching. -$this->db->flush_cache() -======================== +**$this->db->flush_cache()** This function deletes all items from the Query Builder cache. +:returns: void + +An example of caching +--------------------- + Here's a usage example:: $this->db->start_cache(); @@ -1033,8 +1101,12 @@ Here's a usage example:: where, like, group_by, having, order_by, set +*********************** +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(). @@ -1063,4 +1135,6 @@ run the query:: .. 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.
\ No newline at end of file + i.e. if you're caching a ``select()`` - select the same field twice. + +:returns: void diff --git a/user_guide_src/source/database/results.rst b/user_guide_src/source/database/results.rst index e0a87a851..e06985130 100644 --- a/user_guide_src/source/database/results.rst +++ b/user_guide_src/source/database/results.rst @@ -4,10 +4,14 @@ Generating Query Results There are several ways to generate query results: +************* +Result Arrays +************* + result() ======== -This function returns the query result as an array of **objects**, or +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:: @@ -20,7 +24,7 @@ loop, like this:: echo $row->body; } -The above function is an alias of result_object(). +The above method is an alias of result_object(). If you run queries that might **not** produce a result, you are encouraged to test the result first:: @@ -53,7 +57,7 @@ instantiate for each result object (note: this class must be loaded) result_array() =============== -This function returns the query result as a pure array, or an empty +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:: @@ -66,10 +70,14 @@ loop, like this:: echo $row['body']; } +*********** +Result Rows +*********** + row() ===== -This function returns a single result row. If your query has more than +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:: @@ -101,7 +109,7 @@ to instantiate the row with:: row_array() =========== -Identical to the above row() function, except it returns an array. +Identical to the above row() method, except it returns an array. Example:: $query = $this->db->query("YOUR QUERY"); @@ -136,7 +144,8 @@ parameter: | **$row = $query->next_row('array')** | **$row = $query->previous_row('array')** -.. note:: all the functions above will load the whole result into memory (prefetching) use unbuffered_row() for processing large result sets. +.. note:: all the methods above will load the whole result into memory + (prefetching) use unbuffered_row() for processing large result sets. unbuffered_row() ================ @@ -163,12 +172,11 @@ the returned value's type:: $query->unbuffered_row('object'); // object $query->unbuffered_row('array'); // associative array -*********************** -Result Helper Functions -*********************** +********************* +Result Helper Methods +********************* -$query->num_rows() -================== +**$query->num_rows()** The number of rows returned by the query. Note: In this example, $query is the variable that the query result object is assigned to:: @@ -181,20 +189,18 @@ is the variable that the query result object is assigned to:: Not all database drivers have a native way of getting the total number of rows for a result set. When this is the case, all of the data is prefetched and count() is manually called on the - resulting array in order to achieve the same functionality. + resulting array in order to achieve the same methodality. -$query->num_fields() -==================== +**$query->num_fields()** The number of FIELDS (columns) returned by the query. Make sure to call -the function using your query result object:: +the method using your query result object:: $query = $this->db->query('SELECT * FROM my_table'); echo $query->num_fields(); -$query->free_result() -===================== +**$query->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 @@ -217,8 +223,7 @@ Example:: echo $row->name; $query2->free_result(); // The $query2 result object will no longer be available -data_seek() -=========== +**data_seek()** This method sets the internal pointer for the next result row to be fetched. It is only useful in combination with ``unbuffered_row()``. diff --git a/user_guide_src/source/database/table_data.rst b/user_guide_src/source/database/table_data.rst deleted file mode 100644 index 744a05154..000000000 --- a/user_guide_src/source/database/table_data.rst +++ /dev/null @@ -1,31 +0,0 @@ -########## -Table Data -########## - -These functions let you fetch table information. - -$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 $table; - } - -$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. diff --git a/user_guide_src/source/database/utilities.rst b/user_guide_src/source/database/utilities.rst index bd40cdadd..0d8137dd7 100644 --- a/user_guide_src/source/database/utilities.rst +++ b/user_guide_src/source/database/utilities.rst @@ -5,15 +5,13 @@ Database Utility Class The Database Utility Class contains methods that help you manage your database. -.. contents:: Table of Contents - - -****************** -Function Reference -****************** +.. contents:: + :local: + :depth: 2 +****************************** 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. @@ -39,7 +37,11 @@ object:: $this->dbutil->some_method() -$this->dbutil->list_databases(); +**************************** +Using the Database Utilities +**************************** + +Retrieve list of database names ================================ Returns an array of database names:: @@ -51,8 +53,9 @@ Returns an array of database names:: echo $db; } -$this->dbutil->database_exists(); -================================= + +Determine If a Database Exists +============================== Sometimes it's helpful to know whether a particular database exists. Returns a boolean TRUE/FALSE. Usage example:: @@ -65,8 +68,8 @@ Returns a boolean TRUE/FALSE. Usage example:: .. note:: Replace *database_name* with the name of the table you are looking for. This method is case sensitive. -$this->dbutil->optimize_table('table_name'); -============================================ +Optimize a Table +================ Permits you to optimize a table using the table name specified in the first parameter. Returns TRUE/FALSE based on success or failure:: @@ -79,8 +82,8 @@ first parameter. Returns TRUE/FALSE based on success or failure:: .. note:: Not all database platforms support table optimization. It is mostly for use with MySQL. -$this->dbutil->repair_table('table_name'); -========================================== +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:: @@ -92,8 +95,8 @@ first parameter. Returns TRUE/FALSE based on success or failure:: .. note:: Not all database platforms support table repairs. -$this->dbutil->optimize_database(); -==================================== +Optimize a Database +=================== Permits you to optimize the database your DB class is currently connected to. Returns an array containing the DB status messages or @@ -111,8 +114,8 @@ FALSE on failure. .. note:: Not all database platforms support table optimization. It it is mostly for use with MySQL. -$this->dbutil->csv_from_result($db_result); -=========================================== +Export a Query Result as a CSV File +=================================== Permits you to generate a CSV file from a query result. The first parameter of the method must contain the result object from your @@ -139,8 +142,8 @@ is used as the enclosure. Example:: simply creates the CSV layout. If you need to write the file use the :doc:`File Helper <../helpers/file_helper>`. -$this->dbutil->xml_from_result($db_result); -=========================================== +Export a Query Result as an XML Document +======================================== Permits you to generate an XML file from a query result. The first parameter expects a query result object, the second may contain an @@ -163,8 +166,12 @@ optional array of config parameters. Example:: simply creates the XML layout. If you need to write the file use the :doc:`File Helper <../helpers/file_helper>`. -$this->dbutil->backup(); -======================== +******************** +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. @@ -182,7 +189,7 @@ backup data can be compressed in either Zip or Gzip format. have root privileges. Usage Example -------------- +============= :: @@ -201,7 +208,7 @@ Usage Example 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:: @@ -219,7 +226,7 @@ parameter of the ``backup()`` method. Example:: $this->dbutil->backup($prefs); Description of Backup Preferences ---------------------------------- +================================= ======================= ======================= ======================= ======================================================================== Preference Default Value Options Description @@ -234,4 +241,76 @@ Preference Default Value Options Descript **add_insert** TRUE TRUE/FALSE Whether 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_checks** TRUE TRUE/FALSE Whether output should keep foreign key checks enabled. -======================= ======================= ======================= ========================================================================
\ No newline at end of file +======================= ======================= ======================= ======================================================================== + +*************** +Class Reference +*************** + +.. class:: CI_DB_utility + + .. method:: backup([$params = array()]) + + :param array $params: An associative array of options + :returns: void + :rtype: void + + Perform a database backup, per user preferences. + + .. method:: database_exists($database_name) + + :param string $database_name: Database name + :returns: TRUE if the database exists, FALSE otherwise + :rtype: bool + + Check for the existence of a database. + + .. method:: list_databases() + + :returns: Array of database names found + :rtype: array + + Retrieve a list of all the database names. + + .. method:: optimize_database() + + :returns: Array of optimization messages or FALSE on failure + :rtype: array + + Optimizes the database. + + .. method:: optimize_table($table_name) + + :param string $table_name: Name of the table to optimize + :returns: Array of optimization messages or FALSE on failure + :rtype: array + + Optimizes a database table. + + .. method:: repair_table($table_name) + + :param string $table_name: Name of the table to repair + :returns: Array of repair messages or FALSE on failure + :rtype: array + + Repairs a database table. + + .. method:: csv_from_results($query[, $delim = ','[, $newline = "\n"[, $enclosure = '"']]]) + + :param object $query: A database result object + :param string $delim: The CSV field delimiter to use + :param string $newline: The newline character to use + :param string $enclosure: The enclosure delimiter to use + :returns: The generated CSV file as a string + :rtype: string + + Translates a database result object into a CSV document. + + .. method:: xml_from_results($query[, $params = array()]) + + :param object $query: A database result object + :param array $params: An associative array of preferences + :returns: The generated XML document as a string + :rtype: string + + Translates a database result object into an XML document.
\ No newline at end of file |