组SQL中最近的条目
我有一个表,在这个表中,我们可以对多个条目使用相同的票号。我想根据列中的Initiated on检索相同票号的最新票号组SQL中最近的条目,sql,sql-server,sql-server-2008,Sql,Sql Server,Sql Server 2008,我有一个表,在这个表中,我们可以对多个条目使用相同的票号。我想根据列中的Initiated on检索相同票号的最新票号 Ticket VendorTicket InitiatedOn Comments 198165 test 2012-08-10 16:31:33.707 test 199485 sagar 2012-08-11 12:36:25.720 sagar 199485 sagar1 2012-08
Ticket VendorTicket InitiatedOn Comments
198165 test 2012-08-10 16:31:33.707 test
199485 sagar 2012-08-11 12:36:25.720 sagar
199485 sagar1 2012-08-11 14:36:25.720 sagar1
199478 kishor 2012-08-11 12:37:21.923 kishor
我已经在存储过程中用T-SQL编写了这个查询,它告诉我xObj={靠近“.”的语法不正确。}
我的T-SQL
`@SQL='Select ''<a href="javascript:editTicketByIDAction('' + CONVERT(VarChar(Max), Ticket) + '')">'' + CONVERT(VarChar(Max),Ticket) + ''</a>'' t1.Ticket,t1.VendorTicket[Vendor Ticket],t1.Comments
From VendorTickets t1
WHERE NotifyOn <= GetDate() And NotifyOn Is Not Null AND
NOT EXISTS
(SELECT * FROM VendorTickets t2
WHERE t1.Ticket = t2.Ticket AND t1.InitiatedOn < t2.InitiatedOn)'`
试试这个:
这将给出每组的最新记录
select * from <table> t join
(select Ticket,max(InitiatedOn) as InitiatedOn
from <table>
group by Ticket)a
on t.Ticket=a.Ticket
and t.InitiatedOn=a.InitiatedOn
如果您可以使用上面的行号
select T.Ticket,
T.VendorTicket,
T.InitiatedOn,
T.Comments
from (
select Ticket,
VendorTicket,
InitiatedOn,
Comments,
row_number() over(partition by Ticket order by InitiatedOn desc) as rn
from YourTable
) T
where T.rn = 1
解决此问题的一般解决方案适用于任何数据库,如下所示:
SELECT * FROM [my_table] t1
WHERE NOT EXISTS (
SELECT * FROM [my_table] t2
WHERE t1.Ticket = t2.Ticket
AND t1.InitiatedOn < t2.InitiatedOn
)
这是这样的:从my_表中获取所有值,其中没有具有相同票证ID和较新日期的票证
注:
如果有两个具有相同InitiateOn值的最新票证,则可能返回重复的票证。
确保在Ticket和initialedon列上都有适当的索引
您使用的是什么数据库?这里有返回重复项的轻微风险。这可能与OP有关,当然这是完美的!我一直在寻找一种方法来做到这一点已经有一段时间了+1.为什么当我对t1中的一个字段执行联接时,没有返回结果?例如,如果t1有一个电话号码字段,而我有一个电话簿表和一个号码字段,那么如何将号码与姓名匹配?@enchance:如果将此作为常规堆栈溢出问题来提问,您可能会得到更好的答案。
SELECT * FROM [my_table] t1
WHERE NOT EXISTS (
SELECT * FROM [my_table] t2
WHERE t1.Ticket = t2.Ticket
AND t1.InitiatedOn < t2.InitiatedOn
)
Select t1.*
from tickets t1
left join tickets t2 on (t1.ticket = t2.ticket and t2.initiatedon > t1.initiatedon)
where t2.ticket is null;
SELECT Ticket,
VendorTicket,
InitiatedOn,
Comments
FROM (
SELECT Ticket,
VendorTicket,
InitiatedOn,
Comments,
ROW_NUMBER() OVER (PARTITION BY Ticket ORDER BY InitiatedOn DESC) AS Row
FROM Table
) AS Q
WHERE Q.Row = 1