Question

这是我试图在MySQL中执行的查询：

DELETE from Connection 
where
(sourceIp , destinationIp,
destinationPort,
sourceServerId,
destinationServerId,
sourceProcessId,
destinationProcessId) IN (Select 
    sourceIp,
        destinationIp,
        destinationPort,
        sourceServerId,
        destinationServerId,
        sourceProcessId,
        destinationProcessId
from
    (Select 
        sourceIp,
            destinationIp,
            destinationPort,
            sourceServerId,
            destinationServerId,
            sourceProcessId,
            destinationProcessId
    from
        Connection

    where
        sourceIp = '12.43.34.53'
        and destinationIp = '12.43.34.65'
        and destinationPort = '3306'
        and ((sourceServerId = '1'
        and destinationServerId = '2'
        and sourceProcessId = '1'
        and destinationProcessId = '2')
        or (sourceServerId IS NULL
        and destinationServerId = '2'
        and destinationProcessId = '2')
        or (sourceServerId = '1'
        and sourceProcessId = '1'
        and destinationServerId is NULL))) as C);

我正在进行多次选择，因为我无法在Clause中指定相同的目标表。上面的查询执行。我的表看起来像这样：

sourceIp，destinationIp，destinationPort，sourceServerId，destinationServerId，sourceProcessId，destinationProcessId ＆＃39; 12.43.34.53＆＃39;，＆＃39; 12.43.34.65＆＃39;，＆＃39; 3306＆＃39;，NULL，＆＃39; 2＆＃39;，NULL，＆＃39; 2＆＃39;
sourceIp，destinationIp，destinationPort，sourceServerId，destinationServerId，sourceProcessId，destinationProcessId ＆＃39; 12.43.34.53＆＃39;，＆＃39; 12.43.34.65＆＃39;，＆＃39; 3306＆＃39;，＆＃39; 1＆＃39;，NULL，＆＃39; 1＆＃ 39;，NULL
sourceIp，destinationIp，destinationPort，sourceServerId，destinationServerId，sourceProcessId，destinationProcessId ＆＃39; 12.43.34.53＆＃39;，＆＃39; 12.43.34.65＆＃39;，＆＃39; 3306＆＃39;，＆＃39; 1＆＃39;，＆＃39; 2＆＃39; ，＆＃39; 1＆＃39;，＆＃39; 2＆＃39;

以上查询仅删除最后一行（＃3）。但是如果在IN处剪切查询并将其余部分作为Select执行，我将获得所有3行。是因为带空值的IN不起作用吗？有关如何修改此查询以使其删除所有3行的任何建议。（所有id和ips以及目标端口一起使表中的行唯一）

Answer 1

哇，你不需要任何这些选择，并且如果这些字段中的任何一个返回IN，那么使用NULL这个容量将不会给你想要的结果..... .....你的问题出在你的WHERE声明中。

上面的清理可以简化为：

DELETE from Connection 
where
    sourceIp = '12.43.34.53'
    and destinationIp = '12.43.34.65'
    and destinationPort = '3306'
    and ((sourceServerId = '1'
    and destinationServerId = '2'
    and sourceProcessId = '1'
    and destinationProcessId = '2')
    or (sourceServerId IS NULL
    and destinationServerId = '2'
    and destinationProcessId = '2')
    or (sourceServerId = '1'
    and sourceProcessId = '1'
    and destinationServerId is NULL))
;

您没有删除正确记录的原因问题是由于您在WHERE子句中的条件优先顺序。我不打算解开这个，因为你的帖子需要一些工作，比如示例数据和期望的结果，因为我确信会有更好的方法来编写你的查询。

删除某些列

1 个答案: