Question

我有一个数据库表，人们通过姓名，工作和城市来识别。我有第二个表格，其中包含每个城市公司中每项工作的分层表示。

假设我在人员表中有3个人：

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

我在作业表中有数千种作业类型/位置组合，其中的一个示例如下。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Person表是一个复合键，所以我不知道如何构造我的查询的start with部分，以便它从三个作业中的每一个开始我指定的城市。

我可以执行三个单独的查询来获得我想要的内容，但这不能很好地扩展。 e.g：

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

除了我指定的三个人之外的所有工作，我怎样才能获得一份不同的清单（或者我可以用一个独特的，如果不可能的包装）？

Answer 1

请试试这个。我没有测试过这个。

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

如何在分层查询中获取不同的元素列表？

2 个答案: