KAT CODE

1) Getting the default database connection:

$db =& JFactory::getDBO();

2) Set the query. Can pass in start and length LIMIT values to shrink the resultset. This will add LIMIT 0,3 to the end.

$db->setQuery($query,0,3);

3) Execute the query. You can call various methods depending on what amount of data is being returned

$db->loadObject() – returns first row as an object. e.g. $obj->field.
$db->loadObjectList() – returns resultset as an object. For multiple records.
$db->loadResult() – returns first field of first row as a value. A single value
$db->loadRow() – returns the first row as an indexed array.
$db->loadAssoc() - returns first row as an associated array.
$db->loadAssocList() - returns resultset as an associated array. For multiple records.
$db->Execute($sql) - Execute sql that doesn't return anything. Pass sql as parameter.

Looping through a resultset:

$db->setQuery($query,0,3);
$rows = $db->loadObjectList();
foreach($rows as $row)
{
	echo $row->fldname;
}

This will create a resultset object with specified field as key index value.

$db->setQuery("SELECT category_id, name FROM category");
$categories = $db->loadObjectList('category_id');