具有多个值的 SQL Pivot-数据库问题

SQL Pivot with multiple values(具有多个值的 SQL Pivot)

本文介绍了具有多个值的 SQL Pivot的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！

问题描述

你好，我有一张这样的桌子:

Hello I have a table like so:

Building    Categories      Properties
-----------------------------------------
Building250 Structure       Steel
Building250 Security        Access Card
Building250 Security        Security Guard
Building250 Security        Fire Alarm System 
Building250 Security        Sprinklered
Building250 Security        Smoke or heat detectors
Building46  Structure       Brick
Building46  Structure       Steel
Building46  Walls           Steel Stud
Building46  Walls           Masonry
Building46  Washroom        OwnSpace
Building46  Washroom        Common
Building46  Security        Access Card
Building46  Security        Burglar Alarm

我需要像这样旋转它:

Building    Structure   Security           Walls       Washroom
----------------------------------------------------------------------------
Building250 Steel       Access Card     
                        Security Guard      
                        Fire Alarm System       
                        Sprinklered     
                        heat detectors      
Building46  Brick       Access Card       Steel Stud    OwnSpace
            Steel       Burglar Alarm     Masonry       Common 
                        Sprinklered

我尝试了 SQL Pivot，但由于它需要聚合，因此它只返回给定类别的 1 个属性.还有其他方法吗?

I tried SQL Pivot, but since it requires an aggregation, it returns only 1 property for a given category. Is there another way?

这是我的 Pivot SQL:

Here's my Pivot SQL:

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

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

set @query = 'SELECT Building, ' + @cols + ' from 
             (
                SELECT Building, Category, Property, from Buildings
            ) x
            pivot 
            (
                min(Property)
                for Category in (' + @cols + ')
            ) p '

execute(@query)

推荐答案

正如您所指出的，Pivot 可以进行聚合，虽然有可能的解决方法，但您可以通过以下方式在不使用 pivot 的情况下完成您需要的工作.您也可以使用与制作动态枢轴相同的方法使其动态化.

As you noted Pivot can do aggregation and while there are workarounds possible you can accomplish what you need without pivot with something like the following. You could also make it dynamic using the same method you would make a dynamic pivot.

Select B.Building, Str.Properties Structure, 
       Sec.Properties Security, Walls.Properties Walls, Wash.Properties Washroom
    From (Select Distinct Building From Table) B
    Left Join Table Str On Str.Building = B.Building And Categories = 'Structure'
    Left Join Table Sec On Sec.Building = B.Building And Categories = 'Security'
    Left Join Table Walls On Walls.Building = B.Building And Categories = 'Walls'
    Left Join Table Wash On Wash.Building = B.Building And Categories = 'Washroom'

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