Question

我正在尝试找到一种运行如下查询的好方法：

SELECT *
  FROM tableA a
 WHERE    a.manager IN (    SELECT id
                                 FROM tableB b
                           CONNECT BY PRIOR b.id = b.manager_id
                           START WITH b.id = 'managerBob')
       OR a.teamLead IN (    SELECT ID
                               FROM tableB b
                         CONNECT BY PRIOR b.ID = b.manager_id
                         START WITH b.ID = 'managerBob')
       OR a.creator IN (    SELECT id
                              FROM tableB b
                        CONNECT BY PRIOR b.id = b.manager_id
                        START WITH b.id = 'managerBob')

正如您所看到的，我正在尝试使用多个WHERE子句，但每个子句在等式的右侧使用相同的数据集。如果我使用多个子句，它似乎运行得非常慢，我很确定这是因为Oracle正在运行每个子查询。有没有办法让这样的工作？

SELECT *
  FROM tableA a
 WHERE    a.manager, 
          a.teamLead, 
          a.creator in (    SELECT id
                                 FROM tableB b
                           CONNECT BY PRIOR b.id = b.manager_id
                           START WITH b.id = 'managerBob')

顺便说一下，我很抱歉，如果这是我可以用谷歌搜索的东西，我不知道该怎么称呼它。

Answer 1

Subquery factoring可能会有所帮助：

WITH people AS
(    SELECT id
       FROM tableB b
    CONNECT BY PRIOR b.id = b.manager_id
      START WITH b.id = 'managerBob'
)
SELECT *
  FROM tableA a
 WHERE    a.manager IN (SELECT id FROM people)
       OR a.teamLead IN (SELECT id FROM people)
       OR a.creator IN (SELECT id FROM people)

Answer 2

你可以这样做：

WITH bob_subordinates AS (
(    SELECT id
       FROM tableB b
 CONNECT BY PRIOR b.id = b.manager_id
 START WITH b.id = 'managerBob')
SELECT * FROM tableA a
 WHERE a.manager in  (select id from bob_subordinates)
    OR a.teamlead in (select id from bob_subordinates)
    or a.creator  in (select id from bob_subordinates)

替代方案（检查DISTINCT的使用：如果表B中的ID不是唯一的，那么这不是等价的）：

WITH bob_subordinates AS (
(    SELECT DISTINCT id
       FROM tableB b
 CONNECT BY PRIOR b.id = b.manager_id
 START WITH b.id = 'managerBob')
SELECT DISTINCT a.*
  FROM tableA a JOIN bob_subordinates b ON b.id IN (a.manager, a.teamlead, a.creator);

Answer 3

根据评论更新 - 尝试

SELECT A.* FROM 
(SELECT bb.id FROM tableB bb CONNECT BY PRIOR bb.id = bb.manager_id START WITH bb.id = 'managerBob') B INNER JOIN TABLEA A ON B.ID IN (A.MANAGER, A.TEAMLEAD, A.CREATOR)

SQL多个共享WHERE条件

3 个答案: