对不起,刚才看错了,呵呵,应该这样写select class_ID,(select count(title) from 表A where class_ID=a.class_ID),(select count(title) from 表A where title='A' and class_ID=a.class_ID), (select count(title) from 表A where title='B' and class_ID=a.class_ID) from 表A a group by class_ID
select class_ID, count(title) as titlenum, (select count(title) from 表A as a where a.class_ID =表A.class_ID and title='A') as Anum, (select count(title) from 表A as a where a.class_ID =表A.class_ID and title='B') as Bnum from 表A group by class_ID
select CLASS_ID ,count(1) as 'titlenum' ,sum(case when TITLE='A' then 1 else 0 end) as 'Anum' ,sum(case when TITLE='B' then 1 else 0 end) as 'Bnum' from A group by CLASS_ID order by CLASS_ID
select CLASS_ID, titlenum = sum(TITLE), Anum = sum(case TITLE when 'A' then 1 else 0 end), Bnum = sum(case TITLE when 'B' then 1 else 0 end)
(select count(title) from 表A where title='B' and class_ID=a.class_ID) from 表A a group by class_ID
count(title) as titlenum,
(select count(title) from 表A as a where a.class_ID =表A.class_ID and title='A') as Anum,
(select count(title) from 表A as a where a.class_ID =表A.class_ID and title='B') as Bnum
from 表A
group by class_ID
,count(1) as 'titlenum'
,sum(case when TITLE='A' then 1 else 0 end) as 'Anum'
,sum(case when TITLE='B' then 1 else 0 end) as 'Bnum'
from A
group by CLASS_ID
order by CLASS_ID
CLASS_ID,
titlenum = sum(TITLE),
Anum = sum(case TITLE when 'A' then 1 else 0 end),
Bnum = sum(case TITLE when 'B' then 1 else 0 end)
from a group by CLASS_ID