假设你在每个表created_datetime列指定最近的一排,我们可以使用ROWNUMBER功能做的工作见本例
declare @ACCOUNTS table (ID_ACC int)
declare @EMAILS table (EMAIL VARCHAR(50), ID_ACC int, CREATED_DATETIME DATETIME)
declare @PHONES table (PHONE VARCHAR(50), ID_ACC int, CREATED_DATETIME DATETIME)
insert into @ACCOUNTS
SELECT '1' ID_ACC
UNION ALL
SELECT '2' ID_ACC
UNION ALL
SELECT '3' ID_ACC
INSERT INTO @EMAILS
SELECT '[email protected]' EMAIL,'1' ID_ACC, '2015-12-14 22:00:00' CREATED_DATETIME
UNION ALL
SELECT '[email protected]' EMAIL,'1' ID_ACC, '2015-12-14 22:53:00'
UNION ALL
SELECT '[email protected]' EMAIL,'3' ID_ACC, '2015-12-14 22:54:00'
UNION ALL
SELECT '[email protected]' EMAIL,'3' ID_ACC, '2015-12-14 22:55:30'
INSERT INTO @PHONES
SELECT '00213555555' PHONE,'1' ID_ACC, '2015-12-14 22:10:00' CREATED_DATETIME
UNION ALL
SELECT '00213554444' PHONES,'2' ID_ACC, '2015-12-14 22:54:00'
UNION ALL
SELECT '00213556666' PHONES,'3' ID_ACC, '2015-12-14 22:54:00'
UNION ALL
SELECT '00213557777' PHONES,'3' ID_ACC, '2015-12-14 23:10:00'
SELECT
*
FROM
(SELECT
ROW_NUMBER() over (partition by A.ID_ACC order by E.CREATED_DATETIME DESC,P.CREATED_DATETIME DESC) AS ROW_ORDER,
A.ID_ACC,
E.EMAIL,
P.PHONE
FROM @ACCOUNTS as A
left join @EMAILS as E
on A.ID_ACC=E.ID_ACC
left join @PHONES as P
on A.ID_ACC=P.ID_ACC) AS TAB
WHERE TAB.ROW_ORDER=1
1)标签所使用的数据库管理系统(我猜应该是sql server)2)发布一些示例数据3)发布您的尝试到目前为止 –
正如@vkp所说,更多的数据将会有用。据说,根据我的经验,加入窗口函数比外部函数更快,应该返回空值。 –
感谢您的反馈!将更新您的建议。干杯,N – nbardach