T-SQL 动态枢轴

T-SQL dynamic pivot(T-SQL 动态枢轴)
本文介绍了T-SQL 动态枢轴的处理方法,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

好的,我有一张看起来像这样的桌子

Ok I have a table that looks like this

ItemID | ColumnName | Value
1      | name       | Peter
1      | phone      | 12345678
1      | email      | peter@host.com
2      | name       | John
2      | phone      | 87654321
2      | email      | john@host.com
3      | name       | Sarah
3      | phone      | 55667788
3      | email      | sarah@host.com

现在我需要把它变成这个:

Now I need to turn that into this:

ItemID | name  | phone    | email
1      | Peter | 12345678 | peter@host.com
2      | John  | 87654321 | john@host.com
3      | Sarah | 55667788 | sarah@host.com

我一直在研究动态枢轴示例,但似乎我无法将它们放入我的场景中.

I have been looking at dynamic pivot examples, but it seems Im not able to fit them into my scenario.

有人可以帮忙吗?

推荐答案

看下面的例子

CREATE TABLE #Table (
        ID INT,
        ColumnName VARCHAR(250),
        Value VARCHAR(250)
)

INSERT INTO #Table SELECT 1,'name','Peter' 
INSERT INTO #Table SELECT 1,'phone','12345678' 
INSERT INTO #Table SELECT 1,'email','peter@host.com' 
INSERT INTO #Table SELECT 2,'name','John' 
INSERT INTO #Table SELECT 2,'phone','87654321' 
INSERT INTO #Table SELECT 2,'email','john@host.com' 
INSERT INTO #Table SELECT 3,'name','Sarah' 
INSERT INTO #Table SELECT 3,'phone','55667788' 
INSERT INTO #Table SELECT 3,'email','sarah@host.com' 

---I assumed your tablename as TESTTABLE--- 
DECLARE @cols NVARCHAR(2000) 
DECLARE @query NVARCHAR(4000) 

SELECT  @cols = STUFF(( SELECT DISTINCT TOP 100 PERCENT 
                                '],[' + t.ColumnName 
                        FROM    #Table AS t 
                        --ORDER BY '],[' + t.ID 
                        FOR XML PATH('') 
                      ), 1, 2, '') + ']' 

SELECT  @cols

SET @query = N'SELECT ID,'+ @cols +' FROM 
(SELECT t1.ID,t1.ColumnName , t1.Value FROM #Table AS t1) p 
PIVOT (MAX([Value]) FOR ColumnName IN ( '+ @cols +' )) 
AS pvt;' 

EXECUTE(@query)

DROP TABLE #Table

这篇关于T-SQL 动态枢轴的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持编程学习网!

本站部分内容来源互联网,如果有图片或者内容侵犯您的权益请联系我们删除!

相关文档推荐

Execute complex raw SQL query in EF6(在EF6中执行复杂的原始SQL查询)
Hibernate reactive No Vert.x context active in aws rds(AWS RDS中的休眠反应性非Vert.x上下文处于活动状态)
Bulk insert with mysql2 and NodeJs throws 500(使用mysql2和NodeJS的大容量插入抛出500)
Flask + PyMySQL giving error no attribute #39;settimeout#39;(FlASK+PyMySQL给出错误,没有属性#39;setTimeout#39;)
auto_increment column for a group of rows?(一组行的AUTO_INCREMENT列?)
Sort by ID DESC(按ID代码排序)