SQL交叉表實例
很簡單的一個東西，見網(wǎng)上好多朋友問“怎么實現(xiàn)交叉表？”，以下是我寫的一個例子，數(shù)據(jù)庫基于SQL SERVER 2000。
-- ======================================================
--交叉表實例
-- ======================================================
建表：
在查詢分析器里運行：
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‘?dāng)?shù)學(xué)‘,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‘?dāng)?shù)學(xué)‘,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(xiàn)：
--用于：交叉表的列數(shù)是確定的（用了這個很不錯！）
select name,sum(case subject when ‘?dāng)?shù)學(xué)‘ then source else 0 end) as ‘?dāng)?shù)學(xué)‘,
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
--用于：交叉表的列數(shù)是不確定的
不確定列，字段2的值范圍不固定。
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
--不確定列數(shù)
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
==============================================================================
交叉表：
CREATE TABLE Test(字段1 VARCHAR(10),字段2 VARCHAR(10),字段3 VARCHAR(10))
INSERT Test SELECT ‘a(chǎn)001‘, ‘01‘ , 12
UNION ALL SELECT ‘a(chǎn)001‘, ‘02‘ , 24
UNION ALL SELECT ‘a(chǎn)002‘, ‘01‘ , 10
UNION ALL SELECT ‘a(chǎn)002‘, ‘03‘ , 5
UNION ALL SELECT ‘a(chǎn)003‘, ‘02‘ , 6
UNION ALL SELECT ‘a(chǎn)004‘, ‘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
