如何在层次查询中获得不同元素的列表？

Question

我有一个数据库表，其中有名字，工作和城市的人。我有第二个桌子，其中包含每个城市公司每项工作的层次结构表示。

假设我在人民桌上有3个人：

[name(PK),title,city]
Jim, Salesman, Houston
Jane, Associate Marketer, Chicago
Bill, Cashier, New York

而且我在工作表中有成千上万的工作类型/位置组合，其样本以下是一个样本。您可以看到层次关系，因为parent_title是标题的外键：

[title,city,pay,parent_title]
Salesman, Houston, $50000, CEO
Cashier, Houston, $25000
CEO, USA, $1000000
Associate Marketer, Chicago, $75000
Senior Marketer, Chicago, $125000

.....

我遇到的问题是我的人桌是一个复合键，所以我不知道如何结构 start with 我的查询的一部分，以便从我指定的城市中的三个作业中的每一个开始。

我可以执行三个单独的查询以获取我想要的东西，但这并不是很好。例如：

select * from jobs
start with city = (select city from people where name = 'Bill') and title = (select title from people where name = 'Bill')
connect by prior parent_title = title
UNION
select * from jobs
start with city = (select city from people where name = 'Jim') and title = (select title from people where name = 'Jim')
connect by prior parent_title = title
UNION
select * from jobs
start with city = (select city from people where name = 'Jane') and title = (select title from people where name = 'Jane')
connect by prior parent_title = title

在我指定的三个人之上的所有工作中，我还能如何获得独特的列表（或者我可以用独特的话，如果可能的话，也可以将其包裹起来）？

Answer 1

请尝试。我没有测试过。

SELECT  distinct *
FROM    jobs
START   WITH ( city, title ) IN 
     ( SELECT city, title
       FROM   people
       WHERE  name IN ( 'Bill', 'Jim', 'Jane' )
     )
CONNECT BY PRIOR parent_title = title;

Answer 2

这应该有效：

SQL> SELECT *
  2    FROM jobs
  3   START WITH (title, city) IN (SELECT title, city FROM people)
  4  CONNECT BY PRIOR parent_title = title;

TITLE              CITY           PAY PARENT_TITLE
------------------ ------- ---------- ------------
Associate Marketer Chicago       7500 
Salesman           Houston       5000 CEO
CEO                USA         100000