SQL> with aa as (select '1' a1 from dual 2 union all 3 select '2' a2 from dual 4 union all 5 select '3' a4 from dual) 6 select count(*),zftang_test.a1 from zftang_test,aa where zftang_test.a1(+) = aa.a1 group by zftang_test.a1; COUNT(*) A1 ---------- ---------- 1 1 1 1 2
2 union all
3 select '2' a2 from dual
4 union all
5 select '3' a4 from dual)
6 select count(*),zftang_test.a1 from zftang_test,aa where zftang_test.a1(+)
= aa.a1 group by zftang_test.a1; COUNT(*) A1
---------- ----------
1 1
1
1 2
可以考虑使用decode