方法一 select A.id, A.AA1, A.AA2,count(*) 记录数 from A,B where B.id(+) = A.id ;方法二:(8i以上支持) select A.id, A.AA1, A.AA2, Count( select BB1 from B Where id = A.id ) from A, B;
我现在只选出了A在B中有对应ID的纪录,如果在B中没有与A对应的就取不出来,比如 A: id AA1 AA21 22 33 2 44 55B: id BB1 BB2 1 xx xxx 1 xxy xxxxselect A.id, B.coun from A, (select id, count(*) coun from b group by id ) b where a.id = b.id只选出了 A.id B.coun 1 2但是我希望的是A.id B.coun 1 2 2 0请问我该怎样改?
哈哈!这个问题我还是两角的时候答的!现在都快三星了!select A.id, B.coun from A left join (select id, count(*) coun from b group by id ) b on a.id = b.id
select A.id, A.AA1, A.AA2,count(*) 记录数 from A,B where B.id(+) = A.id ;方法二:(8i以上支持)
select A.id, A.AA1, A.AA2, Count( select BB1 from B Where id = A.id ) from A, B;
A:
id AA1 AA21 22 33
2 44 55B:
id BB1 BB2
1 xx xxx
1 xxy xxxxselect A.id, B.coun from A, (select id, count(*) coun from b group by id ) b where a.id = b.id只选出了
A.id B.coun
1 2但是我希望的是A.id B.coun
1 2
2 0请问我该怎样改?