SQL交叉表實例簡要說明

很簡單的一個東西，見網上好多朋友問“怎麼實現交叉表？”，以下是我引用一個CSDN論壇上例子，數據庫基於SQL SERVER 2000。

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

--交叉表實例

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

建表：

在查詢分析器裏運行：

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'張三',N'語文',60)

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

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

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

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

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

INSERT INTO [test] ([name],[subject],[Source]) values (N'張三',N'英語',100)

Go

 

交叉表語句的實現：

--用於：交叉表的列數是確定的

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

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

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

from test

group by name

 

 

--用於：交叉表的列數是不確定的

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