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(用了这个很不错！)

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

不确定列，字段2的值范围不固定。

create table a

(id VARchar(4),

F2 VARCHAR(2),

F3 INT)

insert a(ID,F2,F3)

select ‘A001‘,‘01‘,12

UNION ALL SELECT ‘A001‘,‘02‘,24

UNION ALL SELECT ‘A002‘,‘01‘,10

UNION ALL SELECT ‘A002‘,‘03‘,5

UNION ALL SELECT ‘A003‘,‘02‘,6

UNION ALL SELECT ‘A004‘,‘04‘,13

--SELECT * FROM A

--不确定列数

declare @sql varchar(8000)

set @sql = ‘select ID,‘

select @sql = @sql + ‘sum(case F2 when ‘‘‘ +F2+‘‘‘

then F3 else ‘‘‘‘ end) as ‘‘‘+ ‘字段(‘+F2+‘)‘‘,‘

from (select distinct F2 from A) as B

select @sql = left(@sql,len(@sql)-1) + ‘ from A group by ID‘

--PRINT @SQL

exec(@sql)

go

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交叉表：

CREATE TABLE Test(字段1 VARCHAR(10),字段2 VARCHAR(10),字段3 VARCHAR(10))

INSERT Test SELECT ‘a001‘, ‘01‘ , 12

UNION ALL SELECT ‘a001‘, ‘02‘ , 24

UNION ALL SELECT ‘a002‘, ‘01‘ , 10

UNION ALL SELECT ‘a002‘, ‘03‘ , 5

UNION ALL SELECT ‘a003‘, ‘02‘ , 6

UNION ALL SELECT ‘a004‘, ‘04‘ , 13

SELECT * FROM Test

SELECT 字段1,

[字段(01)]=MAX(CASE WHEN 字段2 =‘01‘ THEN 字段3 ELSE ‘‘ END),

[字段(02)]=MAX(CASE WHEN 字段2 =‘02‘ THEN 字段3 ELSE ‘‘ END),

[字段(03)]=MAX(CASE WHEN 字段2 =‘03‘ THEN 字段3 ELSE ‘‘ END),

[字段(04)]=MAX(CASE WHEN 字段2 =‘04‘ THEN 字段3 ELSE ‘‘ END)

FROM Test

GROUP BY 字段1