• SQL交叉表实例


    很简单的一个东西,见网上好多朋友问“怎么实现交叉表?”,以下是我写的一个例子,数据库基于SQL SERVER 2000

    -- ======================================================

    --交叉表实例

    -- ======================================================

    建表:

    在查询分析器里运行:

    CREATE TABLE [Test] (

           [id] [int] IDENTITY (1, 1) NOT NULL ,

           [name] [nvarchar] (50) COLLATE Chinese_PRC_CI_AS NULL ,

           [subject] [nvarchar] (50) COLLATE Chinese_PRC_CI_AS NULL ,

           [Source] [numeric](18, 0) NULL

    ) ON [PRIMARY]

    GO

    INSERT INTO [test] ([name],[subject],[Source]) values (N'张三',N'语文',60)

    INSERT INTO [test] ([name],[subject],[Source]) values (N'李四',N'数学',70)

    INSERT INTO [test] ([name],[subject],[Source]) values (N'王五',N'英语',80)

    INSERT INTO [test] ([name],[subject],[Source]) values (N'王五',N'数学',75)

    INSERT INTO [test] ([name],[subject],[Source]) values (N'王五',N'语文',57)

    INSERT INTO [test] ([name],[subject],[Source]) values (N'李四',N'语文',80)

    INSERT INTO [test] ([name],[subject],[Source]) values (N'张三',N'英语',100)

    Go

     

     

    交叉表语句的实现:

    --用于:交叉表的列数是确定的

    select name,sum(case subject when '数学' then source else 0 end) as '数学',

              sum(case subject when '英语' then source else 0 end) as '英语',

                sum(case subject when '语文' then source else 0 end) as '语文'

    from test

    group by name

     

     

     

     

    --用于:交叉表的列数是不确定的

    declare @sql varchar(8000)

    set @sql = 'select name,'

     

     

    select @sql = @sql + 'sum(case subject when '''+subject+'''

                              then source else 0 end) as '''+subject+''','

      from (select distinct subject from test) as a

     

     

    select @sql = left(@sql,len(@sql)-1) + ' from test group by name'

    exec(@sql)

    go

     

     

    运行结果:

     

     

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  • 原文地址:https://www.cnblogs.com/ZetaChow/p/2237480.html
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