query with "IN" parameter

Don't put the first placeholder in parentheses.

What I mean is, instead of

PHP Code:

$sql =  'SELECT x,y,z from TABLE WHERE x IN (?) and y=?'; 


try this

PHP Code:

$x =array('a','b','c');
$y =3;
$sql =  'SELECT x,y,z from TABLE WHERE x IN ? and y=?';
$result = $this->db->query($sql, array($x, $y));