ช่วยออกไอเดียหน่อยค่ะ รหัสแจ้งซ่อมต้องเป็นปีเดือนวันต่อด้วยตัวเลข 20100204001 แล้วนำไปเก็บในฐานข้อมูล

$date_ = date("Ymd");
$ff = mysql_query("select * from repair ") or die(mysql_error());
$num = mysql_num_rows($ff);
if($num > 0)
{
$lastid_sql = mysql_query("SELECT idrepair FROM repair  WHERE  idrepair LIKE '".$date_."%' ORDER BY idrepair DESC") or die(mysql_error());
$num_cus = mysql_num_rows($lastid_sql);
if($num_cus > 0)
{
$last_id = mysql_fetch_row($lastid_sql);
$lastid = $last_id[0];
$str = explode("E",$lastid);
$add_date = $str[0];
$customer_id = $str[1];
$i = $num_cus+1;
$idrepair=$date_."E".substr("00000".$i,-4,4);
}
else
{
 $i=1;
$idrepair=$date_."E".substr("00000".$i,-4,4);
}
} else {
 $i=1;
 //$cus_number=$date_."E".$i;
 $idrepair=$date_."E".substr("00000".$i,-4,4);
}