Question

帮助构建SQL查询：

Select Distinct ilc.itemnum, id.itemname, statename, realname
From hsi.itemlc ilc
INNER JOIN hsi.itemdata id ON
id.itemnum = ilc.itemnum
INNER JOIN hsi.lcstate lcs ON
lcs.statenum = ilc.statenum
INNER JOIN hsi.useraccount ua ON
ua.usernum = id.usernum
INNER JOIN hsi.wftransactionlog wft ON
id.itemnum = wft.itemnum

Where ilc.statenum not in ('143','144')
and ilc.lcnum in ('101','252')
and ilc.status <> 16

在我最后一次加入hsi.wftransactionlog时，我只想在id.itemnum = wft.itemnum时拉出最大的wft.logdate。完成此任务的最佳方法是什么？ hsi.wftransactionlog中有几个“itemnum”，但我只想在最近的wft.logdate中获取表中的匹配项。

如果这没有意义，请告诉我。

Answer 1

您可以对子查询使用CROSS APPLY：

SELECT DISTINCT ilc.itemnum, id.itemname, statename, realname
From hsi.itemlc ilc
INNER JOIN hsi.itemdata id ON
id.itemnum = ilc.itemnum
INNER JOIN hsi.lcstate lcs ON
lcs.statenum = ilc.statenum
INNER JOIN hsi.useraccount ua ON
ua.usernum = id.usernum
CROSS APPLY ( SELECT MAX(logdate) AS logdate
              FROM hsi.wftransactionlog wft
              WHERE id.itemnum = wft.itemnum
            ) wft1

Answer 2

在黑暗中没有任何要测试的示例数据，但是使用子查询可能对你有效。

Select Distinct ilc.itemnum, id.itemname, statename, realname,
        ( select max(wft.logdate)
            hsi.wftransactionlog wft
            where wft.itemnum = id.itemnum
        ) as logdate
    From hsi.itemlc ilc
    INNER JOIN hsi.itemdata id ON id.itemnum = ilc.itemnum
    INNER JOIN hsi.lcstate lcs ON lcs.statenum = ilc.statenum
    INNER JOIN hsi.useraccount ua ON ua.usernum = id.usernum
    Where ilc.statenum not in ('143','144')
        and ilc.lcnum in ('101','252')
        and ilc.status <> 16

构建SQL查询

2 个答案: