Question

我的表名是虚拟的，它包含6列，其中ID，NAME，TIMESTAMP和其他3列。

我想删除ID，NAME和TIMESTAMP值与其他行匹配的重复行。如果有多个具有相同ID，NAME和TIMESTAMP值的行，则保留一个并删除其他行。

Answer 1

这是解决方案

我刚刚遇到的另一种可能的解决方案：

DELETE n1 FROM names n1, names n2 WHERE n1.id > n2.id AND n1.name = n2.name

如果要保留行ID最低的值OR

DELETE n1 FROM names n1, names n2 WHERE n1.id < n2.id AND n1.name = n2.name

https://stackoverflow.com/a/5770309

DELETE DupRows.*
FROM MyTable AS DupRows
   INNER JOIN (
      SELECT MIN(ID) AS minId, col1, col2
      FROM MyTable
      GROUP BY col1, col2
      HAVING COUNT(*) > 1
   ) AS SaveRows ON SaveRows.col1 = DupRows.col1 AND SaveRows.col2 = DupRows.col2
      AND SaveRows.minId <> DupRows.ID;

Answer 2

这是一个示例代码。这将有助于你完成它。

DELETE duplicate_rows.*
FROM dummy AS duplicate_rows
   INNER JOIN (
      SELECT MIN(id) AS id, name, timestamp
      FROM dummy
      GROUP BY session_id, user_id, category_id
      HAVING COUNT(*) > 1
   ) AS unique_rows 
ON unique_rows.session_id = duplicate_rows.session_id 
AND unique_rows.user_id = duplicate_rows.user_id
AND unique_rows.category_id = duplicate_rows.category_id
AND unique_rows.id <> duplicate_rows.id;

您在此处找到更详细的说明：http://mildcoder.com/delete-duplicate-rows-from-a-mysql-table/

MySql查询根据某些列字段从表中删除重复的行？

2 个答案: