同表比较
A表
cardid          time                  cade     defrr      degds
10        2010-10-12 23:05:06          ds       s34        dfe
10        2010-10-11 23:06:06          das      s344       dfwwe
12        2010-10-10 20:05:06          dds      s34        ddsfe
13        2010-10-12 21:05:06          dees     s3ff4      dfdfe
145       2010-10-15 23:05:06          dggs     s3554      dflke
145       2010-10-15 11:05:06          dhhs     s3jj4      dfrre
561       2010-10-12 23:05:06          djjs     s3jj4      dfgte
结果如下
cardid          time                  cade     defrr      degds
10        2010-10-12 23:05:06          ds       s34        dfe
12        2010-10-10 20:05:06          dds      s34        ddsfe
13        2010-10-12 21:05:06          dees     s3ff4      dfdfe
145       2010-10-15 23:05:06          dggs     s3554      dflke
561       2010-10-12 23:05:06          djjs     s3jj4      dfgte
我的A表中有1000多万条数据,求怎么快捷的可以筛选出我想要的那种结果!
------解决方案--------------------SQL code
select *
from tb t
where not exists (select 1 from tb where cardid = t.cardid and time > t.time)
------解决方案--------------------
SQL code
select * from A t where time=(select max(time) from A where cardid=t.cardid)