Question

我整天都在研究一个“简单”的问题，这让我很生气。我确定我错过了一些明显的东西;但是没有多少搜索能帮助我。

我有一行数据表，如; （TABLE_1）

             Person_1          Person_2         Person_3
PersonID        ABC               DEF              GHI

但是我需要用另一个表中的值替换引用但是与ID列匹配，例如; （TABLE_2）

PersonID      Work_Done
  LMN            298
  GHI            187
  ABC            872
  XYZ            468
  DEF            512

因此返回;

             Person_1          Person_2         Person_3
Work_Done      872               512              187

我使用的是Microsoft SQL Server企业版V8.00.2039，我无法控制源表。

任何帮助（甚至只是谷歌的想法）都会非常感激。

用于生成示例表的SQL;

-- Table_1
SELECT
'ABC' AS Person_1,
'DEF' AS Person_2,
'GHI' AS Person_3
;
-- Table_2
SELECT 'LMN' AS Person_ID, 298 AS Work_Done
UNION ALL
SELECT 'GHI' AS Person_ID, 187 AS Work_Done
UNION ALL
SELECT 'ABC' AS Person_ID, 872 AS Work_Done
UNION ALL
SELECT 'XYZ' AS Person_ID, 468 AS Work_Done
UNION ALL
SELECT 'DEF' AS Person_ID, 512 AS Work_Done
;
--Returning
SELECT
'872' AS Person_1,
'512' AS Person_2,
'187' AS Person_3;

Answer 1

由于您无法更改设计，因此以下是检索所需内容的代码：

SELECT Person_1 = a.Work_Done
, Person_2 = b.Work_Done
, Person_3 = c.Work_Done
FROM Table1 t
   JOIN Table2 a ON t.Person_1 = a.Person_ID
   JOIN Table2 b ON t.Person_2 = b.Person_ID
   JOIN Table2 c ON t.Person_3 = c.Person_ID

多个连接到同一个表的别名（表2）

Answer 2

SELECT  *
FROM
(
    SELECT  unpvt.Person_Type, b.Work_Done
    FROM    Table_1 a
    UNPIVOT ( Person_ID FOR Person_Type IN (a.[Person_1], a.[Person_2], a.[Person_3]) ) unpvt
    JOIN    Table_2 b ON unpvt.Person_ID = b.Person_ID
) c
PIVOT   ( MAX(c.Work_Done) FOR c.Person_Type IN ([Person_1], [Person_2], [Person_3]) ) pvt

SQL Fiddle

Answer 3

DO PIVOT
http://technet.microsoft.com/en-us/library/ms177410(v=sql.105).aspx

请注意，如果您想要使用不同的组合，则需要使用嵌入式SQL和EXEC @sql

请注意FOR FOR Person_ID IN（[ABC]，[DEF]，[LMN]，[GHI]，[XYZ]）
当你做@sql时，[ABC]是你需要小心'撇号'的表的列。

SELECT 
  * 
FROM(

SELECT 'LMN' AS Person_ID,  298   AS Work_Done 
UNION ALL
SELECT 'GHI' AS Person_ID, 187 AS Work_Done  
UNION ALL
SELECT 'ABC' AS Person_ID, 872 AS Work_Done 
UNION ALL
SELECT 'XYZ' AS Person_ID, 468 AS Work_Done 
UNION ALL
SELECT 'DEF' AS Person_ID, 512 AS Work_Done 


) as datasourcetable
PIVOT
(
 SUM(Work_Done ) 
FOR Person_ID IN ([ABC], [DEF],[LMN],[GHI],[XYZ])

) AS PivotTable;

TSQL'查找'功能 - 困惑

3 个答案: