Selecting Data in Codeigniter

The following functions allow you to build SQL SELECT statements.

 If you are using PHP 5 you can use method chaining for more compact syntax. This is described at the end of the page.

$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('tablename');

// Produces: SELECT * FROM tablename

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

$query = $this->db->get('tablename', 10, 20);

// Produces: SELECT * FROM tablename 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('tablename');

foreach ($query->result() as $row)
{
    echo $row->title;
}

$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('tablename', 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('tablename');

// Produces: SELECT title, content, date FROM tablename

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('tablename');

$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('tablename');

$query = $this->db->get();

// Produces: SELECT title, content, date FROM tablename

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.

1. Simple key/value method: $this->db->where('name', $name);
   
   // Produces: WHERE name = 'Joe'

Notice that the equal sign is added for you.

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

$this->db->where('name', $name);
$this->db->where('title', $title);
$this->db->where('status', $status);

// WHERE name = 'Joe' AND title = 'boss' AND status = 'active'

2. Custom key/value method:

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

$this->db->where('name !=', $name);
$this->db->where('id <', $id);

// Produces: WHERE name != 'Joe' AND id < 45

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

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

$array = array('name !=' => $name, 'id <' => $id, 'date >' => $date);

$this->db->where($array);

4. 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.

1. 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%'

If you do not want to use the wildcard (%) you can pass to the optional third argument the option 'none'. $this->db->like('title', 'match', 'none');
// Produces: WHERE title LIKE 'match'

2. 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