ทำไมผมใช้ DISTINCT ไม่ได้ครับ คือไม่อยากให้ค่าที่ซ้ำกันออกมาโชว์อะครับ

SELECT     DISTINCT(detail.detail_id) detail.id_detail, detail.ThaiName, detail.EngName, tel.id_tel, fax.fax, contact.con_name, contact.c_name, contact.c_lastname, contact_tel.c_tel
FROM         detail INNER JOIN
                      contact ON detail.id_detail = contact.id_detail INNER JOIN
                      contact_tel ON contact.id_con = contact_tel.id_con INNER JOIN
                      tel ON detail.id_detail = tel.id_detail INNER JOIN
                      fax ON detail.id_detail = fax.id_detail
WHERE     (detail.Enable = 'T')