ORA-00904：子查詢中的無效標識符

Question

爲什麼下面的查詢在oracle中不起作用？

select * from ENTITY_OWNERSHIP EO 
where 
(select count (*) 
    from (
     select USER_ID 
     from ENTITY_OWNERSHIP 
     where ENTITY_OWNERSHIP.ENTITY_ID = EO.ENTITY_ID 
    ) 
) > 0 

它產生「ORA-00904：」EO「。」ENTITY_ID「：無效標識符」。但是，當我用精確值替換EO.ENTITY_ID時，例如，10181然後它可以工作。

UPDATE： 完整的查詢看起來像：

select * from ENTITY_OWNERSHIP EO 
where 
(select count (*) 
    from (
     select USER_ID 
     from ENTITY_OWNERSHIP 
     where ENTITY_OWNERSHIP.ENTITY_ID = EO.ENTITY_ID 

     intersect 

     select distinct group_id 
     from USERS.GROUPS 
     start with GROUP_ID in (select GROUP_ID from USERS.LK_GROUPS where USER_ID=10001) 
     connect by prior PARENTGROUP_ID=GROUP_ID 
    ) 
) > 0 

Answer 1

如果你去的基礎，一個相關Subquery先後獲得了相關表格。但是當有一個INNERsubquery，該INNER Query將嘗試執行第一個...因此，其他條件的表不能被訪問，因爲它們在那個時間點不可用。 快捷方式來了解這位是...在對方的回答中提到..

SELECT A.* FROM TABLE A 
WHERE EXISTS 
(SELECT 'X' FROM TABLE B WHERE B.ID = A.ID) 

現在，相關子查詢可以訪問A.

select * from ENTITY_OWNERSHIP EO 
where 
EXISTS 
(
     select USER_ID 
     from ENTITY_OWNERSHIP 
     where ENTITY_OWNERSHIP.ENTITY_ID = EO.ENTITY_ID 

     intersect 

     select distinct group_id 
     from USERS.GROUPS 
     start with GROUP_ID in (select GROUP_ID 
           from USERS.LK_GROUPS 
          where USER_ID=10001) 
     connect by prior PARENTGROUP_ID=GROUP_ID 
) 

Answer 2

我認爲你可以exists，而不是做到這一點：

select * 
from ENTITY_OWNERSHIP EO 
where exists (
     select USER_ID 
     from ENTITY_OWNERSHIP 
     where ENTITY_OWNERSHIP.ENTITY_ID = EO.ENTITY_ID 

     intersect 

     select distinct group_id 
     from USERS.GROUPS 
     start with GROUP_ID in (select GROUP_ID from USERS.LK_GROUPS where USER_ID=10001) 
     connect by prior PARENTGROUP_ID=GROUP_ID 
    );