Step1: Select concatenated PK with combined composite key

$g->select_command = "SELECT concat(Year_No,'-',Order_No,'-',LocationID,'-',TranscationId) as pk,  Year_No, Order_No, LocationID, TranscationId, Startdate, ExpiredDate FROM mylocations ";

Step2: Connect on_update event hander
$e["on_update"] = array("update_data", null, false);
$g->set_events($e);

Step3: In handler, split the PK with your sep, and make custom UPDATE query
function update_data($data)
{
	list($Year_No,$Order_No,$LocationID,$TranscationId) = explode("-",$data["pk"]);

	$s = array();
	foreach($data["params"] as $k=>$v)
	{
		$s[] = "$k = '$v'";
	}
	$s = implode(",",$s);

	$w = "Year_No=$Year_No and Order_No=$Order_No and LocationID=$LocationID and TranscationId=$TranscationId";

	$result1 = mysql_query("UPDATE mylocations set $s WHERE $w");
}