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我有一个无法正常工作的问题。我有 3 张桌子；人员、人员程序和类别。

Person: ID, ....    
PersonProgram: ID, PersonID, Category, Code ...    
Category: ID, ...

Person 表每个人有 1 条记录，PersonProgram 每个人有多个程序。有 4 个类别，我需要将每个人与每个类别的特定程序拉成一行。

人员表：

1
2
3

人员程序表

1, 1, 1, 1
2, 1, 2, 1
3, 1, 1, 3
4, 2, 1, 1
5, 2, 3, 3

期望的结果应该是：

PersonID, ProgramIDforCat1, ProgramIDforCat2, ProgramIDforCat3, ProgramIDforCat4
1, 1, 2, NULL, NULL
2, 1, NULL, 3, NULL

问题是每个人和类别都有多个程序记录，代码为 1、2 或 3。我需要优先考虑代码 1，然后是代码 3，忽略其余部分，同时仍然只提取 1 条记录，或者如果它不存在。

我正在失去它试图让它发挥作用。

仅供参考，它必须在视图中。

谢谢你的帮助。

4

1 回答 1

1 
WITH Person AS
(
SELECT 1 AS ID UNION ALL
SELECT 2 AS ID UNION ALL
SELECT 3 AS ID
),
PersonProgram AS
(
SELECT 1 AS ID, 1 AS PersonID, 1 AS Category, 1 AS Code UNION ALL
SELECT 2, 1, 2, 1 UNION ALL
SELECT 3, 1, 1, 3 UNION ALL
SELECT 4, 2, 1, 1 UNION ALL
SELECT 5, 2, 3, 3
),
pp2 AS
(
SELECT *
,ROW_NUMBER() OVER 
 (PARTITION BY PersonID, Category 
      ORDER BY CASE WHEN Code = 1 THEN 0 ELSE 1 END,
               CASE WHEN Code = 3 THEN 0 ELSE 1 END) AS RN
 FROM PersonProgram
)
select PersonID ,
max(case when Category =1 then pp2.ID end) ProgramIDforCat1,
max(case when Category =2 then pp2.ID end) ProgramIDforCat2,
max(case when Category =3 then pp2.ID end) ProgramIDforCat3,
max(case when Category =4 then pp2.ID end) ProgramIDforCat4
from Person p join pp2 
on pp2.PersonID = p.ID
WHERE RN=1
group by PersonID

退货

PersonID    ProgramIDforCat1 ProgramIDforCat2 ProgramIDforCat3 ProgramIDforCat4
----------- ---------------- ---------------- ---------------- ----------------
1           1                2                NULL             NULL
2           4                NULL             5                NULL

这与您的预期结果不同。pp2.Category（虽然我可以通过使用而不是使其相同pp2.ID）你能澄清一下吗？

于 2010-08-20T22:53:07.607 回答