Warning: mysql_num_rows(): supplied argument is not a valid MySQL result resource in C:\AppServ\www\jobnew\admin_list_position.php on line 20 หมายถึงไรอะครับ
$sql = "select * from tperson where ref_id_position and date_tperson and date_tperson BETWEEN '$ref_id_position' and '$Enter_Date' and '$Enter_Date2' ";
$ref_id_position=$_POST[ref_id_position];
$date_tperson=$_POST[date_tperson];
$sql = "select * from tperson where ref_id_position='$ref_id_position' AND date_tperson BETWEEN '$Enter_Date' and '$Enter_Date2' ";