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假设我有一些这样的数据(日期类型的东西,月/日/年/标志/用户列)

1 - 1 - 2013 flag:1 user:123456
1 - 2 - 2013 flag:0 user:123456
1 - 3 - 2013 flag:0 user:123456
1 - 4 - 2013 flag:0 user:123456
1 - 5 - 2013 flag:1 user:123456
3 - 1 - 2013 flag:1 user:987654
3 - 2 - 2013 flag:0 user:987654
3 - 3 - 2013 flag:0 user:987654
3 - 4 - 2013 flag:0 user:987654
3 - 5 - 2013 flag:1 user:987654

我想从用户 123456 中删除除第一条记录之外的所有记录。我试过:

DELETE FROM table 
WHERE year = 2013 
AND user = 123456 
AND (month != 1 AND day != 1 AND year != 2013 AND flag != 1)

国旗很重要。我很难过。我试过 NOT IN 这样的:

DELETE 
FROM table 
WHERE year = 2013 
AND user = 123456 
NOT IN (SELECT * 
        FROM table 
        WHERE month = 1 AND day = 1 AND year = 2013 AND flag = 1)

但我不能不上班。我究竟做错了什么?

4

1 回答 1

1

您的第一个查询失败,因为year = 2013并且year != 2013不可能。试试下面的修改版本。

DELETE FROM table 
WHERE year = 2013 
AND user = 123456 
AND NOT (month = 1 AND day = 1 AND year = 2013 AND flag = 1)
于 2013-02-20T19:53:20.993 回答