Question

sql 多条数据各自的最大日期

现有表cards，如图：

我现在要取出 sCardNum为同一个的最大的日期的数据，结果如图：

请问用sql该如何实现

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Answer 1

以sCardNum分组，取出最大时间的记录
select * from cards where srcvouchdate in (select MAX(srcvouchdate) from UserList group by sCardNum)

Answer 2

• select * from cards a
  where not exists
  (select 1 from cards where acardnum=a.acardnum and srcvouchdate>a.srcvouchdate)
  

Answer 3

selecct ct.* from (select sCardNum num,max(日期列) dt from cards group by sCardNum) tmp left join  cards ct on ct.sCardNum= tmp.num and ct.日期列=tmp.dt

Answer 4

select * from cards a
where not exists
(select 1 from cards where acardnum=a.acardnum and srcvouchdate>a.srcvouchdate)

Answer 5

select * from cards where scardnum in(select scardnum,max(srcvouchdate) from cards group scardnum);