ช่วยดู SQLให้ทีน่ะค่ะ Where แบบนี้แล้วข้อมูลไม่ขึ้นเลยค่ะ

$sql = "Select  type_code,date_start,date_end,status_2,sender_by,operation_by"; 
$sql .= " From complaint_operation a left outer join complaint_solve b ON a.fiscal_year = b.fiscal_year and a.complaint_no = b.complaint_no";
$sql .= " where operation_by='$operation_by' and status_2='$status' and date_end='$date_end' and date_start='$date_start' ";