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sql的行转列(PIVOT)与列转行(UNPIVOT)

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sql的行转列(PIVOT)与列转行(UNPIVOT)

 

在做数据统计的时候,行转列,列转行是经常碰到的问题。case when方式太麻烦了,而且可扩展性不强,可以使用 PIVOT,UNPIVOT比较快速实现行转列,列转行,而且可扩展性强

一、行转列

1、测试数据准备

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CREATE  TABLE [StudentScores]
(
   [UserName]         NVARCHAR(20),        --学生姓名
   [Subject]          NVARCHAR(30),        --科目
   [Score]            FLOAT,               --成绩
)

INSERT INTO [StudentScores] SELECT '张三', '语文', 80
INSERT INTO [StudentScores] SELECT '张三', '数学', 90
INSERT INTO [StudentScores] SELECT '张三', '英语', 70
INSERT INTO [StudentScores] SELECT '张三', '生物', 85
INSERT INTO [StudentScores] SELECT '李四', '语文', 80
INSERT INTO [StudentScores] SELECT '李四', '数学', 92
INSERT INTO [StudentScores] SELECT '李四', '英语', 76
INSERT INTO [StudentScores] SELECT '李四', '生物', 88
INSERT INTO [StudentScores] SELECT '码农', '语文', 60
INSERT INTO [StudentScores] SELECT '码农', '数学', 82
INSERT INTO [StudentScores] SELECT '码农', '英语', 96
INSERT INTO [StudentScores] SELECT '码农', '生物', 78
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2、行转列sql

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SELECT * FROM [StudentScores] /*数据源*/
AS P
PIVOT 
(
    SUM(Score/*行转列后 列的值*/) FOR 
    p.Subject/*需要行转列的列*/ IN ([语文],[数学],[英语],[生物]/*列的值*/)
) AS T
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执行结果:

二、列转行

1、测试数据准备

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CREATE TABLE ProgrectDetail
(
    ProgrectName         NVARCHAR(20), --工程名称
    OverseaSupply        INT,          --海外供应商供给数量
    NativeSupply         INT,          --国内供应商供给数量
    SouthSupply          INT,          --南方供应商供给数量
    NorthSupply          INT           --北方供应商供给数量
)

INSERT INTO ProgrectDetail
SELECT 'A', 100, 200, 50, 50
UNION ALL
SELECT 'B', 200, 300, 150, 150
UNION ALL
SELECT 'C', 159, 400, 20, 320
UNION ALL
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2、列转行的sql

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SELECT P.ProgrectName,P.Supplier,P.SupplyNum
FROM 
(
    SELECT ProgrectName, OverseaSupply, NativeSupply,
           SouthSupply, NorthSupply
     FROM ProgrectDetail
)T
UNPIVOT 
(
    SupplyNum FOR Supplier IN
    (OverseaSupply, NativeSupply, SouthSupply, NorthSupply )
) P
复制代码

执行结果:

标签:INSERT,StudentScores,INTO,转列,UNPIVOT,PIVOT,转行,SELECT
来源: https://www.cnblogs.com/zouhao/p/10532909.html