要删除重复数据，可以使用以下步骤：

1.查找重复数据

使用 GROUP BY 和 HAVING 子句，按照重复的列进行分组，并且只选择出现次数大于1的组。

SELECT column1, column2, ..., COUNT(*) as count
FROM your_table
GROUP BY column1, column2, ...
HAVING COUNT(*) > 1;

2.删除重复数据：

对于每个重复组，保留第一个（id最小）记录，将其余记录删除。

DELETE FROM your_table
WHERE (column1, column2, ...) IN (
   SELECT column1, column2, ...
   FROM your_table
   GROUP BY column1, column2, ...
   HAVING COUNT(*) > 1
) AND id NOT IN (
   SELECT MIN(id)
   FROM your_table
   GROUP BY column1, column2, ...
   HAVING COUNT(*) > 1
);

3.注意：

上述删除SQL出现如下报错：

 You can‘t specify target table ‘表名‘ for update in FROM clause

意思是说不能依据某字段值做判断再来更新某字段的值，修改sql：

DELETE FROM your_table
WHERE (column1, column2, ...) IN (
   SELECT t1.column1, t2.column2, ... FROM (
       SELECT column1, column2, ...
       FROM your_table
       GROUP BY column1, column2, ...
       HAVING COUNT(*) > 1
   ) AS t1
) AND id NOT IN (
       SELECT t2.min_id FROM(
       SELECT MIN(id)
       FROM your_table
       GROUP BY column1, column2, ...
       HAVING COUNT(*) > 1
   ) AS t2
);