From 7efad20597ef7e06f8cf837a9f40918d2d3f2727 Mon Sep 17 00:00:00 2001 From: Jamie Rumbelow Date: Sun, 19 Feb 2012 12:37:00 +0000 Subject: Renaming Active Record to Query Builder across the system --- user_guide_src/source/database/active_record.rst | 1008 ---------------------- user_guide_src/source/database/configuration.rst | 12 +- user_guide_src/source/database/connecting.rst | 2 +- user_guide_src/source/database/examples.rst | 8 +- user_guide_src/source/database/index.rst | 4 +- user_guide_src/source/database/queries.rst | 2 +- user_guide_src/source/database/query_builder.rst | 1008 ++++++++++++++++++++++ 7 files changed, 1022 insertions(+), 1022 deletions(-) delete mode 100644 user_guide_src/source/database/active_record.rst create mode 100644 user_guide_src/source/database/query_builder.rst (limited to 'user_guide_src/source/database') diff --git a/user_guide_src/source/database/active_record.rst b/user_guide_src/source/database/active_record.rst deleted file mode 100644 index c04e67d2a..000000000 --- a/user_guide_src/source/database/active_record.rst +++ /dev/null @@ -1,1008 +0,0 @@ -################### -Active Record Class -################### - -CodeIgniter uses a modified version of the Active Record Database -Pattern. 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 Active Record 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. - -.. contents:: Page Contents - -************** -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 = $this->db->get('mytable', 10, 20); - // Produces: SELECT * FROM mytable LIMIT 20, 10 (in MySQL. Other databases have slightly different syntax) - -You'll notice that the above function is assigned to a variable named -$query, which can be used to show the results:: - - $query = $this->db->get('mytable'); - - foreach ($query->result() as $row) - { - echo $row->title; - } - -Please visit the :doc:`result functions ` page for a full -discussion regarding result generation. - -$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 $sql; - - // Produces string: SELECT * FROM mytable - -The second parameter enables you to set whether or not the active record query -will be reset (by default it will be—just like `$this->db->get()`):: - - echo $this->db->limit(10,20)->get_compiled_select('mytable', FALSE); - // Produces string: SELECT * FROM mytable LIMIT 20, 10 - // (in MySQL. Other databases have slightly different syntax) - - echo $this->db->select('title, content, date')->get_compiled_select(); - - // Produces string: SELECT title, content, date FROM mytable - -The key thing to notice in the above example is that the second query did not -utilize `$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 = $this->db->get('mytable'); // Produces: SELECT title, content, date FROM mytable - - -.. note:: If you are selecting all (\*) from a table you do not need to - use this function. When omitted, CodeIgniter assumes you wish to SELECT * - -$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 -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 = $this->db->get('mytable'); - - -$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. - -:: - - $this->db->join('comments', 'comments.id = blogs.id', 'left'); - // Produces: LEFT JOIN comments ON comments.id = blogs.id - -$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. - -#. **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' - -#. **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 - -#. **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); - -#. **Custom string:** - You can write your own clauses manually:: - - $where = "name='Joe' AND status='boss' OR status='active'"; - $this->db->where($where); - - -$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 -with backticks. - -:: - - $this->db->where('MATCH (field) AGAINST ("value")', NULL, FALSE); - - -$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', $names); - // Produces: OR username NOT IN ('Frank', 'Todd', 'James') - - -$this->db->like() -================= - -This function enables you to generate **LIKE** clauses, useful for doing -searches. - -.. note:: All values passed to this function are escaped automatically. - -#. **Simple key/value method:** - - :: - - $this->db->like('title', 'match'); // Produces: WHERE title LIKE '%match%' - - If you use multiple function calls they will be chained together with - AND between them:: - - $this->db->like('title', 'match'); - $this->db->like('body', 'match'); - // WHERE title LIKE '%match%' AND body LIKE '%match% - - 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' - $this->db->like('title', 'match', 'after'); // Produces: WHERE title LIKE 'match%' - $this->db->like('title', 'match', 'both'); // Produces: WHERE title LIKE '%match%' - -#. **Associative array method:** - - :: - - $array = array('title' => $match, 'page1' => $match, 'page2' => $match); - $this->db->like($array); - // WHERE title LIKE '%match%' AND page1 LIKE '%match%' AND page2 LIKE '%match%' - - -$this->db->or_like() -==================== - -This function is identical to the one above, except that multiple -instances are joined by OR:: - - $this->db->like('title', 'match'); $this->db->or_like('body', $match); - // WHERE title LIKE '%match%' OR body LIKE '%match%' - -.. note:: or_like() was formerly known as orlike(), which has been removed. - -$this->db->not_like() -===================== - -This function is identical to **like()**, except that it generates NOT -LIKE statements:: - - $this->db->not_like('title', 'match'); // WHERE title NOT LIKE '%match% - -$this->db->or_not_like() -======================== - -This function is identical to **not_like()**, except that multiple -instances are joined by OR:: - - $this->db->like('title', 'match'); - $this->db->or_not_like('body', 'match'); - // WHERE title LIKE '%match% OR body NOT LIKE '%match%' - -$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". - -$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 or desc, or 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"); - $this->db->order_by("name", "asc"); // Produces: ORDER BY title DESC, name ASC - - -.. note:: order_by() was formerly known as orderby(), which has been - removed. - -.. note:: random ordering is not currently supported in Oracle or MSSQL - drivers. These will default to 'ASC'. - -$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 Active Record 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 $this->db->count_all_results(); // Produces an integer, like 17 - -$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 { - var $title = 'My Title'; - var $content = 'My Content'; - var $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 $sql; - - // Produces string: INSERT INTO mytable (title, name, date) VALUES ('My title', 'My name', 'My date') - -The second parameter enables you to set whether or not the active record query -will be reset (by default it will be--just like `$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 $this->db->set('content', 'My Content')->get_compiled_insert(); - - // Produces string: INSERT INTO mytable (title, content) VALUES ('My Title', 'My Content') - -The key thing to notice in the above example is that the second query did not -utlize `$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()`_. - -$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', $data); - // Produces: INSERT INTO mytable (title, name, date) VALUES ('My title', 'My name', 'My date'), ('Another title', 'Another name', 'Another date') - -The first parameter will contain the table name, the second is an -associative array of values. - -.. note:: All values are escaped automatically producing safer queries. - -$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->insert('mytable'); // gives INSERT INTO mytable (field) VALUES (field+1) - $this->db->set('field', 'field+1'); - $this->db->insert('mytable'); // gives INSERT INTO mytable (field) VALUES ('field+1') - - -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 { - var $title = 'My Title'; - var $content = 'My Content'; - var $date = 'My Date'; - } - */ - - $object = new Myclass; - $this->db->set($object); - $this->db->insert('mytable'); - - -************* -Updating Data -************* - -$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 { - var $title = 'My Title'; - var $content = 'My Content'; - var $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', $data, 'title'); - - // Produces: - // UPDATE `mytable` SET `name` = CASE - // WHEN `title` = 'My title' THEN 'My Name 2' - // WHEN `title` = 'Another title' THEN 'Another Name 2' - // ELSE `name` END, - // `date` = CASE - // WHEN `title` = 'My title' THEN 'My date 2' - // WHEN `title` = 'Another title' THEN 'Another date 2' - // ELSE `date` END - // WHERE `title` IN ('My title','Another title') - -The first parameter will contain the table name, the second is an associative -array of values, the third parameter is the where key. - -.. note:: All values are escaped automatically producing safer queries. - -$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()`_. - - -************* -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', $id) - ->limit(10, 20) - ->get('mytable'); - -.. _ar-caching: - -********************* -Active Record Caching -********************* - -While not "true" caching, Active Record enables you to save (or "cache") -certain parts of your queries for reuse at a later point in your -script's execution. Normally, when an Active Record call is completed, -all stored information is reset for the next call. With caching, you can -prevent this reset, and reuse information easily. - -Cached calls are cumulative. If you make 2 cached select() calls, and -then 2 uncached select() calls, this will result in 4 select() calls. -There are three Caching functions available: - -$this->db->start_cache() -======================== - -This function must be called to begin caching. All Active Record 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 Active Record cache. - -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'); - $this->db->get('tablename'); - //Generates: SELECT `field2` FROM (`tablename`) - - -.. note:: The following statements can be cached: select, from, join, - where, like, group_by, having, order_by, set - - -$this->db->reset_query() -======================== - -Resetting Active Record allows you to start fresh with your query without -executing it first using a method like $this->db->get() or $this->db->insert(). -Just like the methods that execute a query, this will *not* reset items you've -cached using `Active Record Caching`_. - -This is useful in situations where you are using Active Record to generate SQL -(ex. ``$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; diff --git a/user_guide_src/source/database/configuration.rst b/user_guide_src/source/database/configuration.rst index 040e7e33f..953bbfbcb 100644 --- a/user_guide_src/source/database/configuration.rst +++ b/user_guide_src/source/database/configuration.rst @@ -106,18 +106,18 @@ 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. -Active Record +Query Builder ------------- -The :doc:`Active Record Class ` is globally enabled or -disabled by setting the $active_record variable in the database +The :doc:`Query Builder Class ` 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 -active record class, setting it to FALSE will utilize fewer resources +query builder class, setting it to FALSE will utilize fewer resources when the database classes are initialized. :: - $active_record = TRUE; + $query_builder = TRUE; .. note:: that some CodeIgniter classes such as Sessions require Active Records be enabled to access certain functionality. @@ -134,7 +134,7 @@ Explanation of Values: **database** The name of the database you want to connect to. **dbdriver** The database type. ie: mysql, postgres, odbc, etc. Must be specified in lower case. **dbprefix** An optional table prefix which will added to the table name when running :doc: - `Active Record ` queries. This permits multiple CodeIgniter installations + `Query Builder ` queries. This permits multiple CodeIgniter installations to share one database. **pconnect** TRUE/FALSE (boolean) - Whether to use a persistent connection. **db_debug** TRUE/FALSE (boolean) - Whether database errors should be displayed. diff --git a/user_guide_src/source/database/connecting.rst b/user_guide_src/source/database/connecting.rst index a834cc0f7..4db038e1e 100644 --- a/user_guide_src/source/database/connecting.rst +++ b/user_guide_src/source/database/connecting.rst @@ -36,7 +36,7 @@ Available Parameters string. #. TRUE/FALSE (boolean). Whether to return the connection ID (see Connecting to Multiple Databases below). -#. TRUE/FALSE (boolean). Whether to enable the Active Record class. Set +#. TRUE/FALSE (boolean). Whether to enable the Query Builder class. Set to TRUE by default. Manually Connecting to a Database diff --git a/user_guide_src/source/database/examples.rst b/user_guide_src/source/database/examples.rst index d1cd48837..8b3cc4701 100644 --- a/user_guide_src/source/database/examples.rst +++ b/user_guide_src/source/database/examples.rst @@ -104,10 +104,10 @@ Standard Insert $this->db->query($sql); echo $this->db->affected_rows(); -Active Record Query +Query Builder Query =================== -The :doc:`Active Record Pattern ` gives you a simplified +The :doc:`Query Builder Pattern ` gives you a simplified means of retrieving data:: $query = $this->db->get('table_name'); @@ -118,10 +118,10 @@ means of retrieving data:: } The above get() function retrieves all the results from the supplied -table. The :doc:`Active Record ` class contains a full +table. The :doc:`Query Builder ` class contains a full compliment of functions for working with data. -Active Record Insert +Query Builder Insert ==================== :: diff --git a/user_guide_src/source/database/index.rst b/user_guide_src/source/database/index.rst index ab12b7cb7..7ccb8fb00 100644 --- a/user_guide_src/source/database/index.rst +++ b/user_guide_src/source/database/index.rst @@ -3,7 +3,7 @@ The Database Class ################## CodeIgniter comes with a full-featured and very fast abstracted database -class that supports both traditional structures and Active Record +class that supports both traditional structures and Query Builder patterns. The database functions offer clear, simple syntax. .. toctree:: @@ -15,7 +15,7 @@ patterns. The database functions offer clear, simple syntax. Running Queries Generating Query Results Query Helper Functions - Active Record Class + Query Builder Class Transactions Table MetaData Field MetaData diff --git a/user_guide_src/source/database/queries.rst b/user_guide_src/source/database/queries.rst index 971d5d61d..2ba3d3f4a 100644 --- a/user_guide_src/source/database/queries.rst +++ b/user_guide_src/source/database/queries.rst @@ -50,7 +50,7 @@ Protecting identifiers ********************** In many databases it is advisable to protect table and field names - for -example with backticks in MySQL. **Active Record queries are +example with backticks in MySQL. **Query Builder queries are automatically protected**, however if you need to manually protect an identifier you can use:: diff --git a/user_guide_src/source/database/query_builder.rst b/user_guide_src/source/database/query_builder.rst new file mode 100644 index 000000000..f55d8e2f7 --- /dev/null +++ b/user_guide_src/source/database/query_builder.rst @@ -0,0 +1,1008 @@ +################### +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. + +.. contents:: Page Contents + +************** +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 = $this->db->get('mytable', 10, 20); + // Produces: SELECT * FROM mytable LIMIT 20, 10 (in MySQL. Other databases have slightly different syntax) + +You'll notice that the above function is assigned to a variable named +$query, which can be used to show the results:: + + $query = $this->db->get('mytable'); + + foreach ($query->result() as $row) + { + echo $row->title; + } + +Please visit the :doc:`result functions ` page for a full +discussion regarding result generation. + +$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 $sql; + + // Produces string: SELECT * FROM mytable + +The second parameter enables you to set whether or not the query builder query +will be reset (by default it will be—just like `$this->db->get()`):: + + echo $this->db->limit(10,20)->get_compiled_select('mytable', FALSE); + // Produces string: SELECT * FROM mytable LIMIT 20, 10 + // (in MySQL. Other databases have slightly different syntax) + + echo $this->db->select('title, content, date')->get_compiled_select(); + + // Produces string: SELECT title, content, date FROM mytable + +The key thing to notice in the above example is that the second query did not +utilize `$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 = $this->db->get('mytable'); // Produces: SELECT title, content, date FROM mytable + + +.. note:: If you are selecting all (\*) from a table you do not need to + use this function. When omitted, CodeIgniter assumes you wish to SELECT * + +$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 +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 = $this->db->get('mytable'); + + +$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. + +:: + + $this->db->join('comments', 'comments.id = blogs.id', 'left'); + // Produces: LEFT JOIN comments ON comments.id = blogs.id + +$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. + +#. **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' + +#. **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 + +#. **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); + +#. **Custom string:** + You can write your own clauses manually:: + + $where = "name='Joe' AND status='boss' OR status='active'"; + $this->db->where($where); + + +$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 +with backticks. + +:: + + $this->db->where('MATCH (field) AGAINST ("value")', NULL, FALSE); + + +$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', $names); + // Produces: OR username NOT IN ('Frank', 'Todd', 'James') + + +$this->db->like() +================= + +This function enables you to generate **LIKE** clauses, useful for doing +searches. + +.. note:: All values passed to this function are escaped automatically. + +#. **Simple key/value method:** + + :: + + $this->db->like('title', 'match'); // Produces: WHERE title LIKE '%match%' + + If you use multiple function calls they will be chained together with + AND between them:: + + $this->db->like('title', 'match'); + $this->db->like('body', 'match'); + // WHERE title LIKE '%match%' AND body LIKE '%match% + + 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' + $this->db->like('title', 'match', 'after'); // Produces: WHERE title LIKE 'match%' + $this->db->like('title', 'match', 'both'); // Produces: WHERE title LIKE '%match%' + +#. **Associative array method:** + + :: + + $array = array('title' => $match, 'page1' => $match, 'page2' => $match); + $this->db->like($array); + // WHERE title LIKE '%match%' AND page1 LIKE '%match%' AND page2 LIKE '%match%' + + +$this->db->or_like() +==================== + +This function is identical to the one above, except that multiple +instances are joined by OR:: + + $this->db->like('title', 'match'); $this->db->or_like('body', $match); + // WHERE title LIKE '%match%' OR body LIKE '%match%' + +.. note:: or_like() was formerly known as orlike(), which has been removed. + +$this->db->not_like() +===================== + +This function is identical to **like()**, except that it generates NOT +LIKE statements:: + + $this->db->not_like('title', 'match'); // WHERE title NOT LIKE '%match% + +$this->db->or_not_like() +======================== + +This function is identical to **not_like()**, except that multiple +instances are joined by OR:: + + $this->db->like('title', 'match'); + $this->db->or_not_like('body', 'match'); + // WHERE title LIKE '%match% OR body NOT LIKE '%match%' + +$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". + +$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 or desc, or 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"); + $this->db->order_by("name", "asc"); // Produces: ORDER BY title DESC, name ASC + + +.. note:: order_by() was formerly known as orderby(), which has been + removed. + +.. note:: random ordering is not currently supported in Oracle or MSSQL + drivers. These will default to 'ASC'. + +$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 $this->db->count_all_results(); // Produces an integer, like 17 + +$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 { + var $title = 'My Title'; + var $content = 'My Content'; + var $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 $this->db->set('content', 'My Content')->get_compiled_insert(); + + // Produces string: INSERT INTO mytable (title, content) VALUES ('My Title', 'My Content') + +The key thing to notice in the above example is that the second query did not +utlize `$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()`_. + +$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', $data); + // Produces: INSERT INTO mytable (title, name, date) VALUES ('My title', 'My name', 'My date'), ('Another title', 'Another name', 'Another date') + +The first parameter will contain the table name, the second is an +associative array of values. + +.. note:: All values are escaped automatically producing safer queries. + +$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->insert('mytable'); // gives INSERT INTO mytable (field) VALUES (field+1) + $this->db->set('field', 'field+1'); + $this->db->insert('mytable'); // gives INSERT INTO mytable (field) VALUES ('field+1') + + +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 { + var $title = 'My Title'; + var $content = 'My Content'; + var $date = 'My Date'; + } + */ + + $object = new Myclass; + $this->db->set($object); + $this->db->insert('mytable'); + + +************* +Updating Data +************* + +$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 { + var $title = 'My Title'; + var $content = 'My Content'; + var $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', $data, 'title'); + + // Produces: + // UPDATE `mytable` SET `name` = CASE + // WHEN `title` = 'My title' THEN 'My Name 2' + // WHEN `title` = 'Another title' THEN 'Another Name 2' + // ELSE `name` END, + // `date` = CASE + // WHEN `title` = 'My title' THEN 'My date 2' + // WHEN `title` = 'Another title' THEN 'Another date 2' + // ELSE `date` END + // WHERE `title` IN ('My title','Another title') + +The first parameter will contain the table name, the second is an associative +array of values, the third parameter is the where key. + +.. note:: All values are escaped automatically producing safer queries. + +$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()`_. + + +************* +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', $id) + ->limit(10, 20) + ->get('mytable'); + +.. _ar-caching: + +********************* +Query Builder Caching +********************* + +While not "true" caching, Query Builder enables you to save (or "cache") +certain parts of your queries for reuse at a later point in your +script's execution. Normally, when an Query Builder call is completed, +all stored information is reset for the next call. With caching, you can +prevent this reset, and reuse information easily. + +Cached calls are cumulative. If you make 2 cached select() calls, and +then 2 uncached select() calls, this will result in 4 select() calls. +There are three Caching functions available: + +$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. + +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'); + $this->db->get('tablename'); + //Generates: SELECT `field2` FROM (`tablename`) + + +.. note:: The following statements can be cached: select, from, join, + where, like, group_by, having, order_by, set + + +$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; -- cgit v1.2.3-24-g4f1b