Question

3表中的详细信息列不断更新我想获取最新的lastUpdateTime 给定的日期时间其中ID与3表匹配

tblClient
ID,     AddressDetail, lastUpdateTime
789     Address     '2013-09-27 00:00:00:000'
789     Address     '2013-09-23 00:00:00:000'
897     Address     '2013-09-22 00:00:00:000'
354     Address     '2013-09-28 00:00:00:000'

tblOrder
ID,     OrdersDetail, lastUpdateTime
789     Order       '2013-09-26 00:00:00:000'
897     Order       '2013-09-30 00:00:00:000'
897     Order       '2013-09-27 00:00:00:000'
354     Order       '2013-09-30 00:00:00:000'

tblAccount
ID,     AccountDetail, lastUpdateTime
789     Detail      '2013-09-23 00:00:00:000'
897     Detail      '2013-09-25 00:00:00:000'
354     Detail      '2013-09-28 00:00:00:000'

- 这不会这样做

SELECT a.ID,a.AccountDetail,max(A.lastUpdateTime)   
From tblClient A
left join tblOrder B
on A.ID = B.ID
left join tblAccount C
on C.ID = A.ID 
where A.LastUpdateTime between '2013-09-20 00:00:00:000' and '2013-09-30 00:00:00:000'

Answer 1

使用UNION而不是JOIN，订购结果然后为每个ID取第一行：

SELECT ID, detail, LastUpdateTime
FROM (
 SELECT ID, detail, LastUpdateTime,
  ROW_NUMBER() OVER (PARTITION BY ID ORDER BY LastUpdateTime desc) rownum
 FROM (
  SELECT ID, AddressDetail as detail, lastUpdateTime
  From tblClient
  WHERE LastUpdateTime between '2013-09-20 00:00:00:000' and '2013-09-30 00:00:00:000'
 UNION
  SELECT ID, orderDetail, lastUpdateTime
  From tblOrder
  WHERE LastUpdateTime between '2013-09-20 00:00:00:000' and '2013-09-30 00:00:00:000'
 UNION
  SELECT ID, AccountDetail, lastUpdateTime
  From tblAccount
  WHERE LastUpdateTime between '2013-09-20 00:00:00:000' and '2013-09-30 00:00:00:000'
 ) x
) y
WHERE rownum = 1

请参阅SQLFiddle

这样做的另一个好处是还会返回最新行的详细信息列。

3个表的最后更新时间

1 个答案: