List page events

Hello,
Can the 'select...from' like the one below be used on the list page events?
{
global $conn,$where,$strTableName;

$str = "select field1 from population where table1.id=".$_SESSION[$strTableName."_masterkey1"];

$rs = db_query($str,$conn);

$data1 = db_fetch_array($rs);
$values['field']=$data1['field1'];
}