delete t1 from tdb_goods as t1 ?LEFT JOIN (select goods_id,goods_name from tdb_goods GROUP BY GOODS_NAME having count(goods_name)>=2 )as t2 on t1.goods_name = t2.goods_name where t1.goods_id >t2.goods_id;

實測用INNER JOIN也可以 為什么不用INNER呢 感覺更合邏輯？ 這里的話感覺JOIN沒有實際意義 只是引出了后邊t2表的定義。