Database queries (select)

Remarks#

For more information on database queries, take a look at the Selecting data using JDatabase

Ordering and setting a limit

Ordering the results and setting a limit can easily be achieved with 2 additional lines added to the chain, like so:

$db = JFactory::getDbo();

$query = $db->getQuery(true);
$query->select('*')
      ->from('#__users')
      ->where('username = '. $db->q('John'))
      ->order('id DESC')
      ->setLimit(15, 0);
 
$db->setQuery($query);

$results = $db->loadObjectList();

This orders the results by id in descending order showing only the first 15 records.

The setLimit() function takes 2 parameters. limit and offset. In the example above, we’re only taking 15 records starting from the first row.

Simple select query

A simple query that selects all users from the #__users table with a username that matches John

$db = JFactory::getDbo();

$query = $db->getQuery(true);
$query->select('*');
$query->from('#__users');
$query->where('username = '. $db->q('John'));
 
$db->setQuery($query);

$results = $db->loadObjectList();

You can also chain the query to improve readability and reduce the SQL code like so:

$db = JFactory::getDbo();

$query = $db->getQuery(true);
$query->select('*')
      ->from('#__users')
      ->where('username = '. $db->q('John'));
 
$db->setQuery($query);

$results = $db->loadObjectList();

Note that in this example, we have used $db->q() which is the shorthand methods for $db->quote()