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authorMike Funk <mfunk@xulonpress.com>2011-10-10 16:31:56 +0200
committerMike Funk <mfunk@xulonpress.com>2011-10-10 16:31:56 +0200
commit8afb848fded8fbdfa24b72df7f067e960c83c0e8 (patch)
treebf3d8fa70610253cb13a87c1aa9d634dcee9f413 /user_guide_src/source/database
parent25246b6b29d87ad7a4f304a7b5623c9f57953356 (diff)
parentbdbe6d222c15e9d1b42a8ee3a3e7fe04b753c1ba (diff)
Codeigniter develop latest.
Diffstat (limited to 'user_guide_src/source/database')
-rw-r--r--user_guide_src/source/database/active_record.rst856
-rw-r--r--user_guide_src/source/database/caching.rst162
-rw-r--r--user_guide_src/source/database/call_function.rst39
-rw-r--r--user_guide_src/source/database/configuration.rst126
-rw-r--r--user_guide_src/source/database/connecting.rst132
-rw-r--r--user_guide_src/source/database/examples.rst136
-rw-r--r--user_guide_src/source/database/fields.rst80
-rw-r--r--user_guide_src/source/database/forge.rst268
-rw-r--r--user_guide_src/source/database/helpers.rst98
-rw-r--r--user_guide_src/source/database/index.rst29
-rw-r--r--user_guide_src/source/database/queries.rst114
-rw-r--r--user_guide_src/source/database/results.rst186
-rw-r--r--user_guide_src/source/database/table_data.rst31
-rw-r--r--user_guide_src/source/database/transactions.rst127
-rw-r--r--user_guide_src/source/database/utilities.rst224
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+###################
+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 $row->title;
+ }
+
+Please visit the :doc:`result functions <results>` page for a full
+discussion regarding result generation.
+
+$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 $this->db->count_all('my_table'); // Produces an integer, like 25
+
+**************
+Inserting Data
+**************
+
+$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->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', $data, 'title');
+
+ // Produces:
+ // UPDATE `mytable` SET `name` = CASE
+ // WHEN `title` = 'My title' THEN 'My Name 2'
+ // WHEN `title` = 'Another title' THEN 'Another Name 2'
+ // ELSE `name` END,
+ // `date` = CASE
+ // WHEN `title` = 'My title' THEN 'My date 2'
+ // WHEN `title` = 'Another title' THEN 'Another date 2'
+ // ELSE `date` END
+ // WHERE `title` IN ('My title','Another title')
+
+The first parameter will contain the table name, the second is an associative
+array of values, the third parameter is the where key.
+
+.. note:: All values are escaped automatically producing safer queries.
+
+
+*************
+Deleting Data
+*************
+
+$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".
+
+***************
+Method Chaining
+***************
+
+Method chaining allows you to simplify your syntax by connecting
+multiple functions. Consider this example::
+
+ $query = $this->db->select('title')
+ ->where('id', $id)
+ ->limit(10, 20)
+ ->get('mytable');
+
+.. note:: Method chaining only works with PHP 5.
+
+.. _ar-caching:
+
+*********************
+Active Record Caching
+*********************
+
+While not "true" caching, Active Record enables you to save (or "cache")
+certain parts of your queries for reuse at a later point in your
+script's execution. Normally, when an Active Record call is completed,
+all stored information is reset for the next call. With caching, you can
+prevent this reset, and reuse information easily.
+
+Cached calls are cumulative. If you make 2 cached select() calls, and
+then 2 uncached select() calls, this will result in 4 select() calls.
+There are three Caching functions available:
+
+$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
+
+
diff --git a/user_guide_src/source/database/caching.rst b/user_guide_src/source/database/caching.rst
new file mode 100644
index 000000000..d73120a93
--- /dev/null
+++ b/user_guide_src/source/database/caching.rst
@@ -0,0 +1,162 @@
+######################
+Database Caching Class
+######################
+
+The Database Caching Class permits you to cache your queries as text
+files for reduced database load.
+
+.. important:: This class is initialized automatically by the database
+ driver when caching is enabled. Do NOT load this class manually.
+
+.. important:: Not all query result functions are available when you
+ use caching. Please read this page carefully.
+
+Enabling Caching
+================
+
+Caching is enabled in three steps:
+
+- Create a writable directory on your server where the cache files can
+ be stored.
+- Set the path to your cache folder in your
+ application/config/database.php file.
+- Enable the caching feature, either globally by setting the preference
+ in your application/config/database.php file, or manually as
+ described below.
+
+Once enabled, caching will happen automatically whenever a page is
+loaded that contains database queries.
+
+How Does Caching Work?
+======================
+
+CodeIgniter's query caching system happens dynamically when your pages
+are viewed. When caching is enabled, the first time a web page is
+loaded, the query result object will be serialized and stored in a text
+file on your server. The next time the page is loaded the cache file
+will be used instead of accessing your database. Your database usage can
+effectively be reduced to zero for any pages that have been cached.
+
+Only read-type (SELECT) queries can be cached, since these are the only
+type of queries that produce a result. Write-type (INSERT, UPDATE, etc.)
+queries, since they don't generate a result, will not be cached by the
+system.
+
+Cache files DO NOT expire. Any queries that have been cached will remain
+cached until you delete them. The caching system permits you clear
+caches associated with individual pages, or you can delete the entire
+collection of cache files. Typically you'll want to use the housekeeping
+functions described below to delete cache files after certain events
+take place, like when you've added new information to your database.
+
+Will Caching Improve Your Site's Performance?
+=============================================
+
+Getting a performance gain as a result of caching depends on many
+factors. If you have a highly optimized database under very little load,
+you probably won't see a performance boost. If your database is under
+heavy use you probably will see an improved response, assuming your
+file-system is not overly taxed. Remember that caching simply changes
+how your information is retrieved, shifting it from being a database
+operation to a file-system one.
+
+In some clustered server environments, for example, caching may be
+detrimental since file-system operations are so intense. On single
+servers in shared environments, caching will probably be beneficial.
+Unfortunately there is no single answer to the question of whether you
+should cache your database. It really depends on your situation.
+
+How are Cache Files Stored?
+===========================
+
+CodeIgniter places the result of EACH query into its own cache file.
+Sets of cache files are further organized into sub-folders corresponding
+to your controller functions. To be precise, the sub-folders are named
+identically to the first two segments of your URI (the controller class
+name and function name).
+
+For example, let's say you have a controller called blog with a function
+called comments that contains three queries. The caching system will
+create a cache folder called blog+comments, into which it will write
+three cache files.
+
+If you use dynamic queries that change based on information in your URI
+(when using pagination, for example), each instance of the query will
+produce its own cache file. It's possible, therefore, to end up with
+many times more cache files than you have queries.
+
+Managing your Cache Files
+=========================
+
+Since cache files do not expire, you'll need to build deletion routines
+into your application. For example, let's say you have a blog that
+allows user commenting. Whenever a new comment is submitted you'll want
+to delete the cache files associated with the controller function that
+serves up your comments. You'll find two delete functions described
+below that help you clear data.
+
+Not All Database Functions Work with Caching
+============================================
+
+Lastly, we need to point out that the result object that is cached is a
+simplified version of the full result object. For that reason, some of
+the query result functions are not available for use.
+
+The following functions ARE NOT available when using a cached result
+object:
+
+- num_fields()
+- field_names()
+- field_data()
+- free_result()
+
+Also, the two database resources (result_id and conn_id) are not
+available when caching, since result resources only pertain to run-time
+operations.
+
+******************
+Function Reference
+******************
+
+$this->db->cache_on() / $this->db->cache_off()
+================================================
+
+Manually enables/disables caching. This can be useful if you want to
+keep certain queries from being cached. Example::
+
+ // Turn caching on
+ $this->db->cache_on();
+ $query = $this->db->query("SELECT * FROM mytable");
+
+ // Turn caching off for this one query
+ $this->db->cache_off();
+ $query = $this->db->query("SELECT * FROM members WHERE member_id = '$current_user'");
+
+ // Turn caching back on
+ $this->db->cache_on();
+ $query = $this->db->query("SELECT * FROM another_table");
+
+$this->db->cache_delete()
+==========================
+
+Deletes the cache files associated with a particular page. This is
+useful if you need to clear caching after you update your database.
+
+The caching system saves your cache files to folders that correspond to
+the URI of the page you are viewing. For example, if you are viewing a
+page at example.com/index.php/blog/comments, the caching system will put
+all cache files associated with it in a folder called blog+comments. To
+delete those particular cache files you will use::
+
+ $this->db->cache_delete('blog', 'comments');
+
+If you do not use any parameters the current URI will be used when
+determining what should be cleared.
+
+$this->db->cache_delete_all()
+===============================
+
+Clears all existing cache files. Example::
+
+ $this->db->cache_delete_all();
+
diff --git a/user_guide_src/source/database/call_function.rst b/user_guide_src/source/database/call_function.rst
new file mode 100644
index 000000000..9890fc453
--- /dev/null
+++ b/user_guide_src/source/database/call_function.rst
@@ -0,0 +1,39 @@
+#####################
+Custom Function Calls
+#####################
+
+$this->db->call_function();
+============================
+
+This function enables you to call PHP database functions that are not
+natively included in CodeIgniter, in a platform independent manner. For
+example, lets say you want to call the mysql_get_client_info()
+function, which is **not** natively supported by CodeIgniter. You could
+do so like this::
+
+ $this->db->call_function('get_client_info');
+
+You must supply the name of the function, **without** the mysql\_
+prefix, in the first parameter. The prefix is added automatically based
+on which database driver is currently being used. This permits you to
+run the same function on different database platforms. Obviously not all
+function calls are identical between platforms, so there are limits to
+how useful this function can be in terms of portability.
+
+Any parameters needed by the function you are calling will be added to
+the second parameter.
+
+::
+
+ $this->db->call_function('some_function', $param1, $param2, etc..);
+
+Often, you will either need to supply a database connection ID or a
+database result ID. The connection ID can be accessed using::
+
+ $this->db->conn_id;
+
+The result ID can be accessed from within your result object, like this::
+
+ $query = $this->db->query("SOME QUERY");
+
+ $query->result_id; \ No newline at end of file
diff --git a/user_guide_src/source/database/configuration.rst b/user_guide_src/source/database/configuration.rst
new file mode 100644
index 000000000..687f0d920
--- /dev/null
+++ b/user_guide_src/source/database/configuration.rst
@@ -0,0 +1,126 @@
+######################
+Database Configuration
+######################
+
+CodeIgniter has a config file that lets you store your database
+connection values (username, password, database name, etc.). The config
+file is located at application/config/database.php. You can also set
+database connection values for specific
+:doc:`environments <../libraries/config>` by placing **database.php**
+it the respective environment config folder.
+
+The config settings are stored in a multi-dimensional array with this
+prototype::
+
+ $db['default']['hostname'] = "localhost";
+ $db['default']['username'] = "root";
+ $db['default']['password'] = "";
+ $db['default']['database'] = "database_name";
+ $db['default']['dbdriver'] = "mysql";
+ $db['default']['dbprefix'] = "";
+ $db['default']['pconnect'] = TRUE;
+ $db['default']['db_debug'] = FALSE;
+ $db['default']['cache_on'] = FALSE;
+ $db['default']['cachedir'] = "";
+ $db['default']['char_set'] = "utf8";
+ $db['default']['dbcollat'] = "utf8_general_ci";
+ $db['default']['swap_pre'] = "";
+ $db['default']['autoinit'] = TRUE;
+ $db['default']['stricton'] = FALSE;
+
+The reason we use a multi-dimensional array rather than a more simple
+one is to permit you to optionally store multiple sets of connection
+values. If, for example, you run multiple environments (development,
+production, test, etc.) under a single installation, you can set up a
+connection group for each, then switch between groups as needed. For
+example, to set up a "test" environment you would do this::
+
+ $db['test']['hostname'] = "localhost";
+ $db['test']['username'] = "root";
+ $db['test']['password'] = "";
+ $db['test']['database'] = "database_name";
+ $db['test']['dbdriver'] = "mysql";
+ $db['test']['dbprefix'] = "";
+ $db['test']['pconnect'] = TRUE;
+ $db['test']['db_debug'] = FALSE;
+ $db['test']['cache_on'] = FALSE;
+ $db['test']['cachedir'] = "";
+ $db['test']['char_set'] = "utf8";
+ $db['test']['dbcollat'] = "utf8_general_ci";
+ $db['test']['swap_pre'] = "";
+ $db['test']['autoinit'] = TRUE;
+ $db['test']['stricton'] = FALSE;
+
+Then, to globally tell the system to use that group you would set this
+variable located in the config file::
+
+ $active_group = "test";
+
+Note: The name "test" is arbitrary. It can be anything you want. By
+default we've used the word "default" for the primary connection, but it
+too can be renamed to something more relevant to your project.
+
+Active Record
+-------------
+
+The :doc:`Active Record Class <active_record>` is globally enabled or
+disabled by setting the $active_record 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
+when the database classes are initialized.
+
+::
+
+ $active_record = TRUE;
+
+.. note:: that some CodeIgniter classes such as Sessions require Active
+ Records be enabled to access certain functionality.
+
+Explanation of Values:
+----------------------
+
+====================== ==================================================================================================
+ Name Config Description
+====================== ==================================================================================================
+**hostname** The hostname of your database server. Often this is "localhost".
+**username** The username used to connect to the database.
+**password** The password used to connect to the database.
+**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 <active_record>` 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.
+**cache_on** TRUE/FALSE (boolean) - Whether database query caching is enabled,
+ see also :doc:`Database Caching Class <caching>`.
+**cachedir** The absolute server path to your database query cache directory.
+**char_set** The character set used in communicating with the database.
+**dbcollat** The character collation used in communicating with the database
+
+ .. note:: For MySQL and MySQLi databases, this setting is only used
+ as a backup if your server is running PHP < 5.2.3 or MySQL < 5.0.7
+ (and in table creation queries made with DB Forge). There is an
+ incompatibility in PHP with mysql_real_escape_string() which can
+ make your site vulnerable to SQL injection if you are using a
+ multi-byte character set and are running versions lower than these.
+ Sites using Latin-1 or UTF-8 database character set and collation are
+ unaffected.
+
+**swap_pre** A default table prefix that should be swapped with dbprefix. This is useful for distributed
+ applications where you might run manually written queries, and need the prefix to still be
+ customizable by the end user.
+**autoinit** Whether or not to automatically connect to the database when the library loads. If set to false,
+ the connection will take place prior to executing the first query.
+**stricton** TRUE/FALSE (boolean) - Whether to force "Strict Mode" connections, good for ensuring strict SQL
+ while developing an application.
+**port** The database port number. To use this value you have to add a line to the database config array.
+ ::
+ $db['default']['port'] = 5432;
+====================== ==================================================================================================
+
+.. note:: Depending on what database platform you are using (MySQL,
+ Postgres, etc.) not all values will be needed. For example, when using
+ SQLite you will not need to supply a username or password, and the
+ database name will be the path to your database file. The information
+ above assumes you are using MySQL.
diff --git a/user_guide_src/source/database/connecting.rst b/user_guide_src/source/database/connecting.rst
new file mode 100644
index 000000000..64adc3047
--- /dev/null
+++ b/user_guide_src/source/database/connecting.rst
@@ -0,0 +1,132 @@
+###########################
+Connecting to your Database
+###########################
+
+There are two ways to connect to a database:
+
+Automatically Connecting
+========================
+
+The "auto connect" feature will load and instantiate the database class
+with every page load. To enable "auto connecting", add the word database
+to the library array, as indicated in the following file:
+
+application/config/autoload.php
+
+Manually Connecting
+===================
+
+If only some of your pages require database connectivity you can
+manually connect to your database by adding this line of code in any
+function where it is needed, or in your class constructor to make the
+database available globally in that class.
+
+::
+
+ $this->load->database();
+
+If the above function does **not** contain any information in the first
+parameter it will connect to the group specified in your database config
+file. For most people, this is the preferred method of use.
+
+Available Parameters
+--------------------
+
+#. The database connection values, passed either as an array or a DSN
+ 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
+ to TRUE by default.
+
+Manually Connecting to a Database
+---------------------------------
+
+The first parameter of this function can **optionally** be used to
+specify a particular database group from your config file, or you can
+even submit connection values for a database that is not specified in
+your config file. Examples:
+
+To choose a specific group from your config file you can do this::
+
+ $this->load->database('group_name');
+
+Where group_name is the name of the connection group from your config
+file.
+
+To connect manually to a desired database you can pass an array of
+values::
+
+ $config['hostname'] = "localhost"; $config['username'] = "myusername"; $config['password'] = "mypassword"; $config['database'] = "mydatabase"; $config['dbdriver'] = "mysql"; $config['dbprefix'] = ""; $config['pconnect'] = FALSE; $config['db_debug'] = TRUE; $config['cache_on'] = FALSE; $config['cachedir'] = ""; $config['char_set'] = "utf8"; $config['dbcollat'] = "utf8_general_ci"; $this->load->database($config);
+
+For information on each of these values please see the :doc:`configuration
+page <configuration>`.
+
+.. note:: For the PDO driver, $config['hostname'] should look like
+ this: 'mysql:host=localhost'
+
+Or you can submit your database values as a Data Source Name. DSNs must
+have this prototype::
+
+ $dsn = 'dbdriver://username:password@hostname/database'; $this->load->database($dsn);
+
+To override default config values when connecting with a DSN string, add
+the config variables as a query string.
+
+::
+
+ $dsn = 'dbdriver://username:password@hostname/database?char_set=utf8&dbcollat=utf8_general_ci&cache_on=true&cachedir=/path/to/cache'; $this->load->database($dsn);
+
+Connecting to Multiple Databases
+================================
+
+If you need to connect to more than one database simultaneously you can
+do so as follows::
+
+ $DB1 = $this->load->database('group_one', TRUE); $DB2 = $this->load->database('group_two', TRUE);
+
+Note: Change the words "group_one" and "group_two" to the specific
+group names you are connecting to (or you can pass the connection values
+as indicated above).
+
+By setting the second parameter to TRUE (boolean) the function will
+return the database object.
+
+.. note:: When you connect this way, you will use your object name to issue
+ commands rather than the syntax used throughout this guide. In other
+ words, rather than issuing commands with:
+
+ |
+ | $this->db->query();
+ | $this->db->result();
+ | etc...
+ |
+ | You will instead use:
+ |
+ | $DB1->query();
+ | $DB1->result();
+ | etc...
+
+Reconnecting / Keeping the Connection Alive
+===========================================
+
+If the database server's idle timeout is exceeded while you're doing
+some heavy PHP lifting (processing an image, for instance), you should
+consider pinging the server by using the reconnect() method before
+sending further queries, which can gracefully keep the connection alive
+or re-establish it.
+
+::
+
+ $this->db->reconnect();
+
+Manually closing the Connection
+===============================
+
+While CodeIgniter intelligently takes care of closing your database
+connections, you can explicitly close the connection.
+
+::
+
+ $this->db->close();
+
diff --git a/user_guide_src/source/database/examples.rst b/user_guide_src/source/database/examples.rst
new file mode 100644
index 000000000..d1cd48837
--- /dev/null
+++ b/user_guide_src/source/database/examples.rst
@@ -0,0 +1,136 @@
+##################################
+Database Quick Start: Example Code
+##################################
+
+The following page contains example code showing how the database class
+is used. For complete details please read the individual pages
+describing each function.
+
+Initializing the Database Class
+===============================
+
+The following code loads and initializes the database class based on
+your :doc:`configuration <configuration>` settings::
+
+ $this->load->database();
+
+Once loaded the class is ready to be used as described below.
+
+Note: If all your pages require database access you can connect
+automatically. See the :doc:`connecting <connecting>` page for details.
+
+Standard Query With Multiple Results (Object Version)
+=====================================================
+
+::
+
+ $query = $this->db->query('SELECT name, title, email FROM my_table');
+
+ foreach ($query->result() as $row)
+ {
+ echo $row->title;
+ echo $row->name;
+ echo $row->email;
+ }
+
+ echo 'Total Results: ' . $query->num_rows();
+
+The above result() function returns an array of **objects**. Example:
+$row->title
+
+Standard Query With Multiple Results (Array Version)
+====================================================
+
+::
+
+ $query = $this->db->query('SELECT name, title, email FROM my_table');
+
+ foreach ($query->result_array() as $row)
+ {
+ echo $row['title'];
+ echo $row['name'];
+ echo $row['email'];
+ }
+
+The above result_array() function returns an array of standard array
+indexes. Example: $row['title']
+
+Testing for Results
+===================
+
+If you run queries that might **not** produce a result, you are
+encouraged to test for a result first using the num_rows() function::
+
+ $query = $this->db->query("YOUR QUERY");
+ if ($query->num_rows() > 0)
+ {
+ foreach ($query->result() as $row)
+ {
+ echo $row->title;
+ echo $row->name;
+ echo $row->body;
+ }
+ }
+
+Standard Query With Single Result
+=================================
+
+::
+
+ $query = $this->db->query('SELECT name FROM my_table LIMIT 1');
+ $row = $query->row();
+ echo $row->name;
+
+The above row() function returns an **object**. Example: $row->name
+
+Standard Query With Single Result (Array version)
+=================================================
+
+::
+
+ $query = $this->db->query('SELECT name FROM my_table LIMIT 1');
+ $row = $query->row_array();
+ echo $row['name'];
+
+The above row_array() function returns an **array**. Example:
+$row['name']
+
+Standard Insert
+===============
+
+::
+
+ $sql = "INSERT INTO mytable (title, name) VALUES (".$this->db->escape($title).", ".$this->db->escape($name).")";
+ $this->db->query($sql);
+ echo $this->db->affected_rows();
+
+Active Record Query
+===================
+
+The :doc:`Active Record Pattern <active_record>` gives you a simplified
+means of retrieving data::
+
+ $query = $this->db->get('table_name');
+
+ foreach ($query->result() as $row)
+ {
+ echo $row->title;
+ }
+
+The above get() function retrieves all the results from the supplied
+table. The :doc:`Active Record <active_record>` class contains a full
+compliment of functions for working with data.
+
+Active Record Insert
+====================
+
+::
+
+ $data = array(
+ 'title' => $title,
+ 'name' => $name,
+ 'date' => $date
+ );
+
+ $this->db->insert('mytable', $data); // Produces: INSERT INTO mytable (title, name, date) VALUES ('{$title}', '{$name}', '{$date}')
+
diff --git a/user_guide_src/source/database/fields.rst b/user_guide_src/source/database/fields.rst
new file mode 100644
index 000000000..b706ace7d
--- /dev/null
+++ b/user_guide_src/source/database/fields.rst
@@ -0,0 +1,80 @@
+##########
+Field Data
+##########
+
+$this->db->list_fields()
+=========================
+
+Returns an array containing the field names. This query can be called
+two ways:
+
+1. You can supply the table name and call it from the $this->db->
+object::
+
+ $fields = $this->db->list_fields('table_name');
+
+ foreach ($fields as $field)
+ {
+ echo $field;
+ }
+
+2. You can gather the field names associated with any query you run by
+calling the function from your query result object::
+
+ $query = $this->db->query('SELECT * FROM some_table');
+
+ foreach ($query->list_fields() as $field)
+ {
+ echo $field;
+ }
+
+$this->db->field_exists()
+==========================
+
+Sometimes it's helpful to know whether a particular field exists before
+performing an action. Returns a boolean TRUE/FALSE. Usage example::
+
+ if ($this->db->field_exists('field_name', 'table_name'))
+ {
+ // some code...
+ }
+
+.. note:: Replace *field_name* with the name of the column you are looking
+ for, and replace *table_name* with the name of the table you are
+ looking for.
+
+$this->db->field_data()
+========================
+
+Returns an array of objects containing field information.
+
+Sometimes it's helpful to gather the field names or other metadata, like
+the column type, max length, etc.
+
+.. note:: Not all databases provide meta-data.
+
+Usage example::
+
+ $fields = $this->db->field_data('table_name');
+
+ foreach ($fields as $field)
+ {
+ echo $field->name;
+ echo $field->type;
+ echo $field->max_length;
+ echo $field->primary_key;
+ }
+
+If you have run a query already you can use the result object instead of
+supplying the table name::
+
+ $query = $this->db->query("YOUR QUERY");
+ $fields = $query->field_data();
+
+The following data is available from this function if supported by your
+database:
+
+- name - column name
+- max_length - maximum length of the column
+- primary_key - 1 if the column is a primary key
+- type - the type of the column \ No newline at end of file
diff --git a/user_guide_src/source/database/forge.rst b/user_guide_src/source/database/forge.rst
new file mode 100644
index 000000000..bf17e2918
--- /dev/null
+++ b/user_guide_src/source/database/forge.rst
@@ -0,0 +1,268 @@
+####################
+Database Forge Class
+####################
+
+The Database Forge Class contains functions that help you manage your
+database.
+
+.. contents:: Table of Contents
+
+****************************
+Initializing the Forge Class
+****************************
+
+.. important:: In order to initialize the Forge class, your database
+ driver must already be running, since the forge class relies on it.
+
+Load the Forge Class as follows::
+
+ $this->load->dbforge()
+
+Once initialized you will access the functions using the $this->dbforge
+object::
+
+ $this->dbforge->some_function()
+
+$this->dbforge->create_database('db_name')
+============================================
+
+Permits you to create the database specified in the first parameter.
+Returns TRUE/FALSE based on success or failure::
+
+ if ($this->dbforge->create_database('my_db'))
+ {
+ echo 'Database created!';
+ }
+
+$this->dbforge->drop_database('db_name')
+==========================================
+
+Permits you to drop the database specified in the first parameter.
+Returns TRUE/FALSE based on success or failure::
+
+ if ($this->dbforge->drop_database('my_db'))
+ {
+ echo 'Database deleted!';
+ }
+
+****************************
+Creating and Dropping Tables
+****************************
+
+There are several things you may wish to do when creating tables. Add
+fields, add keys to the table, alter columns. CodeIgniter provides a
+mechanism for this.
+
+Adding fields
+=============
+
+Fields are created via an associative array. Within the array you must
+include a 'type' key that relates to the datatype of the field. For
+example, INT, VARCHAR, TEXT, etc. Many datatypes (for example VARCHAR)
+also require a 'constraint' key.
+
+::
+
+ $fields = array(
+ 'users' => array(
+ 'type' => 'VARCHAR',
+ 'constraint' => '100',
+ ),
+ );
+ // will translate to "users VARCHAR(100)" when the field is added.
+
+
+Additionally, the following key/values can be used:
+
+- unsigned/true : to generate "UNSIGNED" in the field definition.
+- default/value : to generate a default value in the field definition.
+- null/true : to generate "NULL" in the field definition. Without this,
+ the field will default to "NOT NULL".
+- auto_increment/true : generates an auto_increment flag on the
+ field. Note that the field type must be a type that supports this,
+ such as integer.
+
+::
+
+ $fields = array(
+ 'blog_id' => array(
+ 'type' => 'INT',
+ 'constraint' => 5,
+ 'unsigned' => TRUE,
+ 'auto_increment' => TRUE
+ ),
+ 'blog_title' => array(
+ 'type' => 'VARCHAR',
+ 'constraint' => '100',
+ ),
+ 'blog_author' => array(
+ 'type' =>'VARCHAR',
+ 'constraint' => '100',
+ 'default' => 'King of Town',
+ ),
+ 'blog_description' => array(
+ 'type' => 'TEXT',
+ 'null' => TRUE,
+ ),
+ );
+
+
+After the fields have been defined, they can be added using
+$this->dbforge->add_field($fields); followed by a call to the
+create_table() function.
+
+$this->dbforge->add_field()
+----------------------------
+
+The add fields function will accept the above array.
+
+Passing strings as fields
+-------------------------
+
+If you know exactly how you want a field to be created, you can pass the
+string into the field definitions with add_field()
+
+::
+
+ $this->dbforge->add_field("label varchar(100) NOT NULL DEFAULT 'default label'");
+
+
+.. note:: Multiple calls to add_field() are cumulative.
+
+Creating an id field
+--------------------
+
+There is a special exception for creating id fields. A field with type
+id will automatically be assinged as an INT(9) auto_incrementing
+Primary Key.
+
+::
+
+ $this->dbforge->add_field('id');
+ // gives id INT(9) NOT NULL AUTO_INCREMENT
+
+
+Adding Keys
+===========
+
+Generally speaking, you'll want your table to have Keys. This is
+accomplished with $this->dbforge->add_key('field'). An optional second
+parameter set to TRUE will make it a primary key. Note that add_key()
+must be followed by a call to create_table().
+
+Multiple column non-primary keys must be sent as an array. Sample output
+below is for MySQL.
+
+::
+
+ $this->dbforge->add_key('blog_id', TRUE);
+ // gives PRIMARY KEY `blog_id` (`blog_id`)
+
+ $this->dbforge->add_key('blog_id', TRUE);
+ $this->dbforge->add_key('site_id', TRUE);
+ // gives PRIMARY KEY `blog_id_site_id` (`blog_id`, `site_id`)
+
+ $this->dbforge->add_key('blog_name');
+ // gives KEY `blog_name` (`blog_name`)
+
+ $this->dbforge->add_key(array('blog_name', 'blog_label'));
+ // gives KEY `blog_name_blog_label` (`blog_name`, `blog_label`)
+
+
+Creating a table
+================
+
+After fields and keys have been declared, you can create a new table
+with
+
+::
+
+ $this->dbforge->create_table('table_name');
+ // gives CREATE TABLE table_name
+
+
+An optional second parameter set to TRUE adds an "IF NOT EXISTS" clause
+into the definition
+
+::
+
+ $this->dbforge->create_table('table_name', TRUE);
+ // gives CREATE TABLE IF NOT EXISTS table_name
+
+
+Dropping a table
+================
+
+Executes a DROP TABLE sql
+
+::
+
+ $this->dbforge->drop_table('table_name');
+ // gives DROP TABLE IF EXISTS table_name
+
+
+Renaming a table
+================
+
+Executes a TABLE rename
+
+::
+
+ $this->dbforge->rename_table('old_table_name', 'new_table_name');
+ // gives ALTER TABLE old_table_name RENAME TO new_table_name
+
+
+****************
+Modifying Tables
+****************
+
+$this->dbforge->add_column()
+=============================
+
+The add_column() function is used to modify an existing table. It
+accepts the same field array as above, and can be used for an unlimited
+number of additional fields.
+
+::
+
+ $fields = array(
+ 'preferences' => array('type' => 'TEXT')
+ );
+ $this->dbforge->add_column('table_name', $fields);
+ // gives ALTER TABLE table_name ADD preferences TEXT
+
+An optional third parameter can be used to specify which existing column
+to add the new column after.
+
+::
+
+ $this->dbforge->add_column('table_name', $fields, 'after_field');
+
+
+$this->dbforge->drop_column()
+==============================
+
+Used to remove a column from a table.
+
+::
+
+ $this->dbforge->drop_column('table_name', 'column_to_drop');
+
+
+$this->dbforge->modify_column()
+================================
+
+The usage of this function is identical to add_column(), except it
+alters an existing column rather than adding a new one. In order to
+change the name you can add a "name" key into the field defining array.
+
+::
+
+ $fields = array(
+ 'old_name' => array(
+ 'name' => 'new_name',
+ 'type' => 'TEXT',
+ ),
+ );
+ $this->dbforge->modify_column('table_name', $fields);
+ // gives ALTER TABLE table_name CHANGE old_name new_name TEXT \ No newline at end of file
diff --git a/user_guide_src/source/database/helpers.rst b/user_guide_src/source/database/helpers.rst
new file mode 100644
index 000000000..7ea19e9f6
--- /dev/null
+++ b/user_guide_src/source/database/helpers.rst
@@ -0,0 +1,98 @@
+######################
+Query Helper Functions
+######################
+
+$this->db->insert_id()
+=======================
+
+The insert ID number when performing database inserts.
+
+.. note:: If using the PDO driver with PostgreSQL, this function requires
+ a $name parameter, which specifies the appropriate sequence to check
+ for the insert id.
+
+$this->db->affected_rows()
+===========================
+
+Displays the number of affected rows, when doing "write" type queries
+(insert, update, etc.).
+
+.. note:: In MySQL "DELETE FROM TABLE" returns 0 affected rows. The database
+ class has a small hack that allows it to return the correct number of
+ affected rows. By default this hack is enabled but it can be turned off
+ in the database driver file.
+
+$this->db->count_all();
+========================
+
+Permits you to determine the number of rows in a particular table.
+Submit the table name in the first parameter. Example::
+
+ echo $this->db->count_all('my_table');
+
+ // Produces an integer, like 25
+
+$this->db->platform()
+=====================
+
+Outputs the database platform you are running (MySQL, MS SQL, Postgres,
+etc...)::
+
+ echo $this->db->platform();
+
+$this->db->version()
+====================
+
+Outputs the database version you are running::
+
+ echo $this->db->version();
+
+$this->db->last_query();
+=========================
+
+Returns the last query that was run (the query string, not the result).
+Example::
+
+ $str = $this->db->last_query();
+
+ // Produces: SELECT * FROM sometable....
+
+The following two functions help simplify the process of writing
+database INSERTs and UPDATEs.
+
+$this->db->insert_string();
+============================
+
+This function simplifies the process of writing database inserts. It
+returns a correctly formatted SQL insert string. Example::
+
+ $data = array('name' => $name, 'email' => $email, 'url' => $url);
+
+ $str = $this->db->insert_string('table_name', $data);
+
+The first parameter is the table name, the second is an associative
+array with the data to be inserted. The above example produces::
+
+ INSERT INTO table_name (name, email, url) VALUES ('Rick', 'rick@example.com', 'example.com')
+
+.. note:: Values are automatically escaped, producing safer queries.
+
+$this->db->update_string();
+============================
+
+This function simplifies the process of writing database updates. It
+returns a correctly formatted SQL update string. Example::
+
+ $data = array('name' => $name, 'email' => $email, 'url' => $url);
+
+ $where = "author_id = 1 AND status = 'active'";
+
+ $str = $this->db->update_string('table_name', $data, $where);
+
+The first parameter is the table name, the second is an associative
+array with the data to be updated, and the third parameter is the
+"where" clause. The above example produces::
+
+ UPDATE table_name SET name = 'Rick', email = 'rick@example.com', url = 'example.com' WHERE author_id = 1 AND status = 'active'
+
+.. note:: Values are automatically escaped, producing safer queries.
diff --git a/user_guide_src/source/database/index.rst b/user_guide_src/source/database/index.rst
new file mode 100644
index 000000000..3b59986be
--- /dev/null
+++ b/user_guide_src/source/database/index.rst
@@ -0,0 +1,29 @@
+##################
+The Database Class
+##################
+
+CodeIgniter comes with a full-featured and very fast abstracted database
+class that supports both traditional structures and Active Record
+patterns. The database functions offer clear, simple syntax.
+
+- :doc:`Quick Start: Usage Examples <examples>`
+- :doc:`Database Configuration <configuration>`
+- :doc:`Connecting to a Database <connecting>`
+- :doc:`Running Queries <queries>`
+- :doc:`Generating Query Results <results>`
+- :doc:`Query Helper Functions <helpers>`
+- :doc:`Active Record Class <active_record>`
+- :doc:`Transactions <transactions>`
+- :doc:`Table MetaData <table_data>`
+- :doc:`Field MetaData <fields>`
+- :doc:`Custom Function Calls <call_function>`
+- :doc:`Query Caching <caching>`
+- :doc:`Database manipulation with Database Forge <forge>`
+- :doc:`Database Utilities Class <utilities>`
+
+.. toctree::
+ :glob:
+ :titlesonly:
+ :hidden:
+
+ * \ No newline at end of file
diff --git a/user_guide_src/source/database/queries.rst b/user_guide_src/source/database/queries.rst
new file mode 100644
index 000000000..971d5d61d
--- /dev/null
+++ b/user_guide_src/source/database/queries.rst
@@ -0,0 +1,114 @@
+#######
+Queries
+#######
+
+$this->db->query();
+===================
+
+To submit a query, use the following function::
+
+ $this->db->query('YOUR QUERY HERE');
+
+The query() function returns a database result **object** when "read"
+type queries are run, which you can use to :doc:`show your
+results <results>`. When "write" type queries are run it simply
+returns TRUE or FALSE depending on success or failure. When retrieving
+data you will typically assign the query to your own variable, like
+this::
+
+ $query = $this->db->query('YOUR QUERY HERE');
+
+$this->db->simple_query();
+===========================
+
+This is a simplified version of the $this->db->query() function. It ONLY
+returns TRUE/FALSE on success or failure. 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.
+
+***************************************
+Working with Database prefixes manually
+***************************************
+
+If you have configured a database prefix and would like to prepend it to
+a table name for use in a native SQL query for example, then you can use
+the following::
+
+ $this->db->dbprefix('tablename'); // outputs prefix_tablename
+
+
+If for any reason you would like to change the prefix programatically
+without needing to create a new connection, you can use this method::
+
+ $this->db->set_dbprefix('newprefix');
+ $this->db->dbprefix('tablename'); // outputs newprefix_tablename
+
+
+**********************
+Protecting identifiers
+**********************
+
+In many databases it is advisable to protect table and field names - for
+example with backticks in MySQL. **Active Record queries are
+automatically protected**, however if you need to manually protect an
+identifier you can use::
+
+ $this->db->protect_identifiers('table_name');
+
+
+This function will also add a table prefix to your table, assuming you
+have a prefix specified in your database config file. To enable the
+prefixing set TRUE (boolen) via the second parameter::
+
+ $this->db->protect_identifiers('table_name', TRUE);
+
+
+****************
+Escaping Queries
+****************
+
+It's a very good security practice to escape your data before submitting
+it into your database. CodeIgniter has three methods that help you do
+this:
+
+#. **$this->db->escape()** This function determines the data type so
+ that it can escape only string data. It also automatically adds
+ single quotes around the data so you don't have to:
+ ::
+
+ $sql = "INSERT INTO table (title) VALUES(".$this->db->escape($title).")";
+
+#. **$this->db->escape_str()** This function escapes the data passed to
+ it, regardless of type. Most of the time you'll use the above
+ function rather than this one. Use the function like this:
+ ::
+
+ $sql = "INSERT INTO table (title) VALUES('".$this->db->escape_str($title)."')";
+
+#. **$this->db->escape_like_str()** This method should be used when
+ strings are to be used in LIKE conditions so that LIKE wildcards
+ ('%', '\_') in the string are also properly escaped.
+
+::
+
+ $search = '20% raise'; $sql = "SELECT id FROM table WHERE column LIKE '%".$this->db->escape_like_str($search)."%'";
+
+
+**************
+Query Bindings
+**************
+
+Bindings enable you to simplify your query syntax by letting the system
+put the queries together for you. Consider the following example::
+
+ $sql = "SELECT * FROM some_table WHERE id = ? AND status = ? AND author = ?";
+ $this->db->query($sql, array(3, 'live', 'Rick'));
+
+The question marks in the query are automatically replaced with the
+values in the array in the second parameter of the query function.
+
+The secondary benefit of using binds is that the values are
+automatically escaped, producing safer queries. You don't have to
+remember to manually escape data; the engine does it automatically for
+you.
diff --git a/user_guide_src/source/database/results.rst b/user_guide_src/source/database/results.rst
new file mode 100644
index 000000000..4f93c794d
--- /dev/null
+++ b/user_guide_src/source/database/results.rst
@@ -0,0 +1,186 @@
+########################
+Generating Query Results
+########################
+
+There are several ways to generate query results:
+
+result()
+========
+
+This function returns the query result as an array of **objects**, or
+**an empty array** on failure. Typically you'll use this in a foreach
+loop, like this::
+
+ $query = $this->db->query("YOUR QUERY");
+
+ foreach ($query->result() as $row)
+ {
+ echo $row->title;
+ echo $row->name;
+ echo $row->body;
+ }
+
+The above function is an alias of result_object().
+
+If you run queries that might **not** produce a result, you are
+encouraged to test the result first::
+
+ $query = $this->db->query("YOUR QUERY");
+
+ if ($query->num_rows() > 0)
+ {
+ foreach ($query->result() as $row)
+ {
+ echo $row->title;
+ echo $row->name;
+ echo $row->body;
+ }
+ }
+
+You can also pass a string to result() which represents a class to
+instantiate for each result object (note: this class must be loaded)
+
+::
+
+ $query = $this->db->query("SELECT * FROM users;");
+
+ foreach ($query->result('User') as $user)
+ {
+ echo $user->name; // call attributes
+ echo $user->reverse_name(); // or methods defined on the 'User' class
+ }
+
+result_array()
+===============
+
+This function returns the query result as a pure array, or an empty
+array when no result is produced. Typically you'll use this in a foreach
+loop, like this::
+
+ $query = $this->db->query("YOUR QUERY");
+
+ foreach ($query->result_array() as $row)
+ {
+ echo $row['title'];
+ echo $row['name'];
+ echo $row['body'];
+ }
+
+row()
+=====
+
+This function returns a single result row. If your query has more than
+one row, it returns only the first row. The result is returned as an
+**object**. Here's a usage example::
+
+ $query = $this->db->query("YOUR QUERY");
+
+ if ($query->num_rows() > 0)
+ {
+ $row = $query->row();
+
+ echo $row->title;
+ echo $row->name;
+ echo $row->body;
+ }
+
+If you want a specific row returned you can submit the row number as a
+digit in the first parameter::
+
+ $row = $query->row(5);
+
+You can also add a second String parameter, which is the name of a class
+to instantiate the row with::
+
+ $query = $this->db->query("SELECT * FROM users LIMIT 1;");
+ $query->row(0, 'User');
+
+ echo $row->name; // call attributes
+ echo $row->reverse_name(); // or methods defined on the 'User' class
+
+row_array()
+============
+
+Identical to the above row() function, except it returns an array.
+Example::
+
+ $query = $this->db->query("YOUR QUERY");
+
+ if ($query->num_rows() > 0)
+ {
+ $row = $query->row_array();
+
+ echo $row['title'];
+ echo $row['name'];
+ echo $row['body'];
+ }
+
+If you want a specific row returned you can submit the row number as a
+digit in the first parameter::
+
+ $row = $query->row_array(5);
+
+In addition, you can walk forward/backwards/first/last through your
+results using these variations:
+
+ | **$row = $query->first_row()**
+ | **$row = $query->last_row()**
+ | **$row = $query->next_row()**
+ | **$row = $query->previous_row()**
+
+By default they return an object unless you put the word "array" in the
+parameter:
+
+ | **$row = $query->first_row('array')**
+ | **$row = $query->last_row('array')**
+ | **$row = $query->next_row('array')**
+ | **$row = $query->previous_row('array')**
+
+***********************
+Result Helper Functions
+***********************
+
+$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::
+
+ $query = $this->db->query('SELECT * FROM my_table');
+
+ echo $query->num_rows();
+
+$query->num_fields()
+=====================
+
+The number of FIELDS (columns) returned by the query. Make sure to call
+the function using your query result object::
+
+ $query = $this->db->query('SELECT * FROM my_table');
+
+ echo $query->num_fields();
+
+$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
+script execution. However, if you are running a lot of queries in a
+particular script you might want to free the result after each query
+result has been generated in order to cut down on memory consumptions.
+Example::
+
+ $query = $this->db->query('SELECT title FROM my_table');
+
+ foreach ($query->result() as $row)
+ {
+ echo $row->title;
+ }
+ $query->free_result(); // The $query result object will no longer be available
+
+ $query2 = $this->db->query('SELECT name FROM some_table');
+
+ $row = $query2->row();
+ echo $row->name;
+ $query2->free_result();// The $query2 result object will no longer be available
+
diff --git a/user_guide_src/source/database/table_data.rst b/user_guide_src/source/database/table_data.rst
new file mode 100644
index 000000000..744a05154
--- /dev/null
+++ b/user_guide_src/source/database/table_data.rst
@@ -0,0 +1,31 @@
+##########
+Table Data
+##########
+
+These functions let you fetch table information.
+
+$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 ($this->db->table_exists('table_name'))
+ {
+ // some code...
+ }
+
+.. note:: Replace *table_name* with the name of the table you are looking for.
diff --git a/user_guide_src/source/database/transactions.rst b/user_guide_src/source/database/transactions.rst
new file mode 100644
index 000000000..e9190e59a
--- /dev/null
+++ b/user_guide_src/source/database/transactions.rst
@@ -0,0 +1,127 @@
+############
+Transactions
+############
+
+CodeIgniter's database abstraction allows you to use transactions with
+databases that support transaction-safe table types. In MySQL, you'll
+need to be running InnoDB or BDB table types rather than the more common
+MyISAM. Most other database platforms support transactions natively.
+
+If you are not familiar with transactions we recommend you find a good
+online resource to learn about them for your particular database. The
+information below assumes you have a basic understanding of
+transactions.
+
+CodeIgniter's Approach to Transactions
+======================================
+
+CodeIgniter utilizes an approach to transactions that is very similar to
+the process used by the popular database class ADODB. We've chosen that
+approach because it greatly simplifies the process of running
+transactions. In most cases all that is required are two lines of code.
+
+Traditionally, transactions have required a fair amount of work to
+implement since they demand that you to keep track of your queries and
+determine whether to commit or rollback based on the success or failure
+of your queries. This is particularly cumbersome with nested queries. In
+contrast, we've implemented a smart transaction system that does all
+this for you automatically (you can also manage your transactions
+manually if you choose to, but there's really no benefit).
+
+Running Transactions
+====================
+
+To run your queries using transactions you will use the
+$this->db->trans_start() and $this->db->trans_complete() functions as
+follows::
+
+ $this->db->trans_start();
+ $this->db->query('AN SQL QUERY...');
+ $this->db->query('ANOTHER QUERY...');
+ $this->db->query('AND YET ANOTHER QUERY...');
+ $this->db->trans_complete();
+
+You can run as many queries as you want between the start/complete
+functions and they will all be committed or rolled back based on success
+or failure of any given query.
+
+Strict Mode
+===========
+
+By default CodeIgniter runs all transactions in Strict Mode. When strict
+mode is enabled, if you are running multiple groups of transactions, if
+one group fails all groups will be rolled back. If strict mode is
+disabled, each group is treated independently, meaning a failure of one
+group will not affect any others.
+
+Strict Mode can be disabled as follows::
+
+ $this->db->trans_strict(FALSE);
+
+Managing Errors
+===============
+
+If you have error reporting enabled in your config/database.php file
+you'll see a standard error message if the commit was unsuccessful. If
+debugging is turned off, you can manage your own errors like this::
+
+ $this->db->trans_start();
+ $this->db->query('AN SQL QUERY...');
+ $this->db->query('ANOTHER QUERY...');
+ $this->db->trans_complete();
+
+ if ($this->db->trans_status() === FALSE)
+ {
+ // generate an error... or use the log_message() function to log your error
+ }
+
+Enabling Transactions
+=====================
+
+Transactions are enabled automatically the moment you use
+$this->db->trans_start(). If you would like to disable transactions you
+can do so using $this->db->trans_off()::
+
+ $this->db->trans_off();
+
+ $this->db->trans_start();
+ $this->db->query('AN SQL QUERY...');
+ $this->db->trans_complete();
+
+When transactions are disabled, your queries will be auto-commited, just
+as they are when running queries without transactions.
+
+Test Mode
+=========
+
+You can optionally put the transaction system into "test mode", which
+will cause your queries to be rolled back -- even if the queries produce
+a valid result. To use test mode simply set the first parameter in the
+$this->db->trans_start() function to TRUE::
+
+ $this->db->trans_start(TRUE); // Query will be rolled back
+ $this->db->query('AN SQL QUERY...');
+ $this->db->trans_complete();
+
+Running Transactions Manually
+=============================
+
+If you would like to run transactions manually you can do so as follows::
+
+ $this->db->trans_begin();
+
+ $this->db->query('AN SQL QUERY...');
+ $this->db->query('ANOTHER QUERY...');
+ $this->db->query('AND YET ANOTHER QUERY...');
+
+ if ($this->db->trans_status() === FALSE)
+ {
+ $this->db->trans_rollback();
+ }
+ else
+ {
+ $this->db->trans_commit();
+ }
+
+.. note:: Make sure to use $this->db->trans_begin() when running manual
+ transactions, **NOT** $this->db->trans_start().
diff --git a/user_guide_src/source/database/utilities.rst b/user_guide_src/source/database/utilities.rst
new file mode 100644
index 000000000..b0920109f
--- /dev/null
+++ b/user_guide_src/source/database/utilities.rst
@@ -0,0 +1,224 @@
+######################
+Database Utility Class
+######################
+
+The Database Utility Class contains functions that help you manage your
+database.
+
+.. contents:: Table of Contents
+
+
+******************
+Function Reference
+******************
+
+Initializing the Utility Class
+==============================
+
+.. important:: In order to initialize the Utility class, your database
+ driver must already be running, since the utilities class relies on it.
+
+Load the Utility Class as follows::
+
+ $this->load->dbutil()
+
+Once initialized you will access the functions using the $this->dbutil
+object::
+
+ $this->dbutil->some_function()
+
+$this->dbutil->list_databases()
+================================
+
+Returns an array of database names::
+
+ $dbs = $this->dbutil->list_databases();
+
+ foreach ($dbs as $db)
+ {
+ echo $db;
+ }
+
+$this->dbutil->database_exists();
+==================================
+
+Sometimes it's helpful to know whether a particular database exists.
+Returns a boolean TRUE/FALSE. Usage example::
+
+ if ($this->dbutil->database_exists('database_name'))
+ {
+ // some code...
+ }
+
+Note: Replace *database_name* with the name of the table you are
+looking for. This function is case sensitive.
+
+$this->dbutil->optimize_table('table_name');
+==============================================
+
+.. note:: This features is only available for MySQL/MySQLi databases.
+
+Permits you to optimize a table using the table name specified in the
+first parameter. Returns TRUE/FALSE based on success or failure::
+
+ if ($this->dbutil->optimize_table('table_name'))
+ {
+ echo 'Success!';
+ }
+
+.. note:: Not all database platforms support table optimization.
+
+$this->dbutil->repair_table('table_name');
+============================================
+
+.. note:: This features is only available for MySQL/MySQLi databases.
+
+Permits you to repair a table using the table name specified in the
+first parameter. Returns TRUE/FALSE based on success or failure::
+
+ if ($this->dbutil->repair_table('table_name'))
+ {
+ echo 'Success!';
+ }
+
+.. note:: Not all database platforms support table repairs.
+
+$this->dbutil->optimize_database();
+====================================
+
+.. note:: This features is only available for MySQL/MySQLi databases.
+
+Permits you to optimize the database your DB class is currently
+connected to. Returns an array containing the DB status messages or
+FALSE on failure.
+
+::
+
+ $result = $this->dbutil->optimize_database();
+
+ if ($result !== FALSE)
+ {
+ print_r($result);
+ }
+
+.. note:: Not all database platforms support table optimization.
+
+$this->dbutil->csv_from_result($db_result)
+=============================================
+
+Permits you to generate a CSV file from a query result. The first
+parameter of the function must contain the result object from your
+query. Example::
+
+ $this->load->dbutil();
+
+ $query = $this->db->query("SELECT * FROM mytable");
+
+ echo $this->dbutil->csv_from_result($query);
+
+The second, third, and fourth parameters allow you to set the delimiter
+newline, and enclosure characters respectively. By default tabs are
+used as the delimiter, "\n" is used as a new line, and a double-quote
+is used as the enclosure. Example::
+
+ $delimiter = ",";
+ $newline = "\r\n";
+ $enclosure = '"';
+
+ echo $this->dbutil->csv_from_result($query, $delimiter, $newline, $enclosure);
+
+.. important:: This function will NOT write the CSV file for you. It
+ simply creates the CSV layout. If you need to write the file
+ use the :doc:`File Helper <../helpers/file_helper>`.
+
+$this->dbutil->xml_from_result($db_result)
+=============================================
+
+Permits you to generate an XML file from a query result. The first
+parameter expects a query result object, the second may contain an
+optional array of config parameters. Example::
+
+ $this->load->dbutil();
+
+ $query = $this->db->query("SELECT * FROM mytable");
+
+ $config = array (
+ 'root' => 'root',
+ 'element' => 'element',
+ 'newline' => "\n",
+ 'tab' => "\t"
+ );
+
+ echo $this->dbutil->xml_from_result($query, $config);
+
+.. important:: This function will NOT write the XML file for you. It
+ simply creates the XML layout. If you need to write the file
+ use the :doc:`File Helper <../helpers/file_helper>`.
+
+$this->dbutil->backup()
+=======================
+
+Permits you to backup your full database or individual tables. The
+backup data can be compressed in either Zip or Gzip format.
+
+.. note:: This features is only available for MySQL databases.
+
+.. note:: Due to the limited execution time and memory available to PHP,
+ backing up very large databases may not be possible. If your database is
+ very large you might need to backup directly from your SQL server via
+ the command line, or have your server admin do it for you if you do not
+ have root privileges.
+
+Usage Example
+-------------
+
+::
+
+ // Load the DB utility class
+ $this->load->dbutil();
+
+ // Backup your entire database and assign it to a variable
+ $backup =& $this->dbutil->backup();
+
+ // Load the file helper and write the file to your server
+ $this->load->helper('file');
+ write_file('/path/to/mybackup.gz', $backup);
+
+ // Load the download helper and send the file to your desktop
+ $this->load->helper('download');
+ force_download('mybackup.gz', $backup);
+
+Setting Backup Preferences
+--------------------------
+
+Backup preferences are set by submitting an array of values to the first
+parameter of the backup function. Example::
+
+ $prefs = array(
+ 'tables' => array('table1', 'table2'), // Array of tables to backup.
+ 'ignore' => array(), // List of tables to omit from the backup
+ 'format' => 'txt', // gzip, zip, txt
+ 'filename' => 'mybackup.sql', // File name - NEEDED ONLY WITH ZIP FILES
+ 'add_drop' => TRUE, // Whether to add DROP TABLE statements to backup file
+ 'add_insert' => TRUE, // Whether to add INSERT data to backup file
+ 'newline' => "\n" // Newline character used in backup file
+ );
+
+ $this->dbutil->backup($prefs);
+
+Description of Backup Preferences
+---------------------------------
+
+=============== ======================= ======================= ========================================================================
+Preference Default Value Options Description
+=============== ======================= ======================= ========================================================================
+**tables** empty array None An array of tables you want backed up. If left blank all tables will be
+ exported.
+**ignore** empty array None An array of tables you want the backup routine to ignore.
+**format** gzip gzip, zip, txt The file format of the export file.
+**filename** the current date/time None The name of the backed-up file. The name is needed only if you are using
+ zip compression.
+**add_drop** TRUE TRUE/FALSE Whether to include DROP TABLE statements in your SQL export file.
+**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.
+=============== ======================= ======================= ======================================================================== \ No newline at end of file