甲骨文左联接返回没有行

Question

我有一个（现在彻底导出）CTE：

feature_id | function_id | group_id | subgroup_id | type_id 
1   1    null  1    null 
1   1    null  null   14 
2   1    null  5    null 
2   1    null  null   21 
3   1    null  7    null 
3   1    null  null   5 

我试图整理在一起使用该行：

select C1.feature_id, C1.function_Id, C2.Group_ID, C3.Subgroup_ID, C4.Type_id 
from CTE C1 
left join CTE C2 
    on C1.feature_id = C2.feature_id 
    and c1.function_id = c2.function_id 
    and c2.group_id is not null 
left join CTE C3 
    on C1.feature_id = C3.feature_id 
    and c1.function_id = c3.function_id 
    and c3.subgroup_id is not null 
left join CTE C4 
    on C1.feature_id = C4.feature_id 
    and c1.function_id = c4.function_id 
    and c4.type_id is not null 

这给我0行。 ..

为了验证，我跑：

select * 
from CTE C1 

选择236行

任何人都可以帮忙吗？当然从C1行应该回来...

编辑：固定它与Oracle语法：

select C1.feature_id, C1.function_Id, C2.Group_ID, C3.Subgroup_ID, C4.Type_id 
from CTE C1, CTE C2, CTE C3, CTE C4 
where C1.feature_id = C2.feature_id(+) 
and c1.function_id = c2.function_id(+) 
and C2.group_id(+) is not null 
... 

（我讨厌甲骨文语法）

Answer 1

好，解决它...

select C1.feature_id, C1.function_Id, C2.Group_ID, C3.Subgroup_ID, C4.Type_id 
from CTE C1, CTE C2, CTE C3, CTE C4 
where C1.feature_id = C2.feature_id(+) 
and c1.function_id = c2.function_id(+) 
and C2.group_id(+) is not null 
... 

（我讨厌甲骨文语法）