MySQL 删除重复行

Question

我有一个 cmets 表，其结构如下：

id, name, email, comment

我有许多重复的 cmets，具有相同的名称和电子邮件。我需要删除它们，谁能建议我如何使用单个查询来实现这一点？

谢谢

Answer 1

DELETE FROM comments c1 

WHERE EXISTS (
    SELECT * 
    FROM comments c2 
    WHERE c2.id <> c1.id 
        AND c2.name = c1.name 
        AND c2.email = c1.email 
        AND c2.comment = c1.comment
)

AND c1.id <> (
    SELECT MIN(c2.id) 
    FROM comments c2 
    WHERE c2.name = c1.name 
        AND c2.email = c1.email 
        AND c2.comment = c1.comment
)