我需要从我的一个表中删除所有重复的记录,问题是没有任何id或唯一或键列,所以我不能做这样的事情:
delete from tbl using tbl,tbl t2 where tbl.locationID=t2.locationID
and tbl.linkID=t2.linkID and tbl.ID>t2.IDRun Code Online (Sandbox Code Playgroud)
因为它需要一个id列或唯一或键列,我不能做一个
ALTER IGNORE TABLE 'mytable' ADD UNIQUE INDEX Run Code Online (Sandbox Code Playgroud)
因为有些信息总是有必要重复,但有些信息没有,我无法做到:
DELETE FROM 'table' WHERE 'field' IN (SELECT 'field' FROM 'table' GROUP BY 'field'HAVING (COUNT('field')>1))Run Code Online (Sandbox Code Playgroud)
因为它会删除所有重复的,永远不会留下一个这是我的表的一个例子
+----------+----------------------+-------------+-------------+
| phone | address | name | cellphone |
+----------+----------------------+-------------+-------------+
| 2555555 | 1020 PANORAMA | JUAN CARLOS | 0999999999 | diferent address
| 2555555 | GABRIEL JOSE 1020 | JUAN CARLOS | 0999999999 | good one
| 2555555 | …Run Code Online (Sandbox Code Playgroud)