MySQL的删除行重复的内容

Question

可能重复：
Remove duplicate rows in MySQL
Delete all Duplicate Rows except for One in MySQL?

这是我的表看起来像

1 | 1 | Hello 
1 | 2 | Hello 
1 | 3 | Hello 
1 | 4 | some text 
1 | 5 | text 
1 | 6 | text 

如何删除所有重复行，只是离开了 最后一个;例如：

1 | 3 | Hello 
1 | 4 | some text 
1 | 6 | text 

任何帮助将不胜感激。

Answer 1

DELETE a 
FROM tableName a 
     LEFT JOIN 
     (
      SELECT col3, col1, MAX(col2) maxCol 
      FROM tableName 
      GROUP BY col3, col1 
     ) b ON a.col1 = b.col1 AND 
       a.col2 = b.maxCol AND 
       a.col3 = b.col3 
WHERE b.col1 IS NULL 

• SQLFiddle Demo