交叉表实例

-- ======================================================
-- 交叉表实例
-- 基于SQL SERVER 2000
-- ======================================================

-- 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

-- 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)

SELECT @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

DROP TABLE TEST
GO
 --摘自优快云,一个经典算法吧