SQL Server 中的动态枢轴列

问题描述

我在 SQL Server 中有一个名为 Property 的表，其中包含以下列:

I have a table named Property with following columns in SQL Server:

Id    Name

这个表中有一些属性，其他表中的某个对象应该赋予它价值.

there are some property in this table that certain object in other table should give value to it.

Id    Object_Id    Property_Id    Value

我想制作一个如下所示的数据透视表，其中我在第一个表中声明的每个属性都有一列:

I want to make a pivot table like below that has one column for each property I've declared in 1'st table:

Object_Id    Property1    Property2    Property3    ...

我想知道如何从表中动态获取数据透视列.因为第一个表中的行会改变.

I want to know how can I get columns of pivot dynamically from table. Because the rows in 1'st table will change.

推荐答案

是这样的:

DECLARE @cols AS NVARCHAR(MAX);
DECLARE @query AS NVARCHAR(MAX);

select @cols = STUFF((SELECT distinct ',' +
                        QUOTENAME(Name)
                      FROM property
                      FOR XML PATH(''), TYPE
                     ).value('.', 'NVARCHAR(MAX)') 
                        , 1, 1, '');

SELECT @query =

'SELECT *
FROM
(
  SELECT
    o.object_id,
    p.Name,
    o.value
  FROM propertyObjects AS o
  INNER JOIN property AS p ON o.Property_Id = p.Id
) AS t
PIVOT 
(
  MAX(value) 
  FOR Name IN( ' + @cols + ' )' +
' ) AS p ; ';

 execute(@query);

SQL Fiddle 演示.

这会给你这样的东西:

SQL Fiddle Demo.

This will give you something like this:

| OBJECT_ID | PROPERTY1 | PROPERTY2 | PROPERTY3 | PROPERTY4 |
-------------------------------------------------------------
|         1 |        ee |        fd |       fdf |      ewre |
|         2 |       dsd |       sss |      dfew |       dff |

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