急求一个查询语句

Question

select count(*)
  from t1, t2
 where t1.peid = t2.peid
不会是这样吧??

Answer 1

To
应该得到如下结果集T1表中的所有记录       +    编号PEID在表T2中对应的记录个数
------------------------------
PEID    NAME    ...    Count(T2.*) Where T2.PEID = T1.PEID

Answer 2

select t1.peid,count(t2.peid) from t1,t2 where t1.peid = t2.peid(+) group by t1.peid

Answer 3

select t1.*,nvl(count(t2.peid),0) as c from t1,t2 where t2.peid=t1.peid 
group by t1.peid

Answer 4

SELECT
T1.*
, COUNT(T2.PEID) OVER ()
FROM T1 LEFT OUTER JOIN T2 ON 
T1.PEID = T2.PEID
;

Answer 5

select t2.*,decode(t1.dd,null,0,t1.dd) test
from test t2,(select count(d) dd,d from test1 group by d) t1
where t2.a=t1.d(+)