由上表求出下表:
名词解释 km:科目 kr:科任 bj:班级 bjlb:班级列表教学分工表(fg)
bj km kr
一01 yw a
一01 sx b
一02 yw a
一02 sx b
一03 yw a
一03 sx c
教师任班表(rb)
kr km bjlb
a yw 一01,一02,一03
b sx 一01,一02
c sx 一03建表代码如下:
create table fg (bj varchar(4),km varchar(4), kr varchar(6))
insert rb select '一01','yw','a' union
select '一01','sx','b' union
select '一02','yw','a' union
select '一02','sx','b' union
select '一03','yw','a' union
select '一03','sx','c'
名词解释 km:科目 kr:科任 bj:班级 bjlb:班级列表教学分工表(fg)
bj km kr
一01 yw a
一01 sx b
一02 yw a
一02 sx b
一03 yw a
一03 sx c
教师任班表(rb)
kr km bjlb
a yw 一01,一02,一03
b sx 一01,一02
c sx 一03建表代码如下:
create table fg (bj varchar(4),km varchar(4), kr varchar(6))
insert rb select '一01','yw','a' union
select '一01','sx','b' union
select '一02','yw','a' union
select '一02','sx','b' union
select '一03','yw','a' union
select '一03','sx','c'
--处理的数据
CREATE TABLE tb(col1 varchar(10),col2 int)
INSERT tb SELECT 'a',1
UNION ALL SELECT 'a',2
UNION ALL SELECT 'b',1
UNION ALL SELECT 'b',2
UNION ALL SELECT 'b',3--合并处理
--定义结果集表变量
DECLARE @t TABLE(col1 varchar(10),col2 varchar(100))--定义游标并进行合并处理
DECLARE tb CURSOR LOCAL
FOR
SELECT col1,col2 FROM tb ORDER BY col1,col2
DECLARE @col1_old varchar(10),@col1 varchar(10),@col2 int,@s varchar(100)
OPEN tb
FETCH tb INTO @col1,@col2
SELECT @col1_old=@col1,@s=''
WHILE @@FETCH_STATUS=0
BEGIN
IF @col1=@col1_old
SELECT @s=@s+','+CAST(@col2 as varchar)
ELSE
BEGIN
INSERT @t VALUES(@col1_old,STUFF(@s,1,1,''))
SELECT @s=','+CAST(@col2 as varchar),@col1_old=@col1
END
FETCH tb INTO @col1,@col2
END
INSERT @t VALUES(@col1_old,STUFF(@s,1,1,''))
CLOSE tb
DEALLOCATE tb
--显示结果并删除测试数据
SELECT * FROM @t
DROP TABLE tb
/*--结果
col1 col2
---------- -----------
a 1,2
b 1,2,3
--*/
GO
/*==============================================*/
--3.3.2 使用用户定义函数,配合SELECT处理完成字符串合并处理的示例
--处理的数据
CREATE TABLE tb(col1 varchar(10),col2 int)
INSERT tb SELECT 'a',1
UNION ALL SELECT 'a',2
UNION ALL SELECT 'b',1
UNION ALL SELECT 'b',2
UNION ALL SELECT 'b',3
GO--合并处理函数
CREATE FUNCTION dbo.f_str(@col1 varchar(10))
RETURNS varchar(100)
AS
BEGIN
DECLARE @re varchar(100)
SET @re=''
SELECT @re=@re+','+CAST(col2 as varchar)
FROM tb
WHERE col1=@col1
RETURN(STUFF(@re,1,1,''))
END
GO--调用函数
SELECT col1,col2=dbo.f_str(col1) FROM tb GROUP BY col1
--删除测试
DROP TABLE tb
DROP FUNCTION f_str
/*--结果
col1 col2
---------- -----------
a 1,2
b 1,2,3
--*/
GO/*==============================================*/
--3.3.3 使用临时表实现字符串合并处理的示例
--处理的数据
CREATE TABLE tb(col1 varchar(10),col2 int)
INSERT tb SELECT 'a',1
UNION ALL SELECT 'a',2
UNION ALL SELECT 'b',1
UNION ALL SELECT 'b',2
UNION ALL SELECT 'b',3--合并处理
SELECT col1,col2=CAST(col2 as varchar(100))
INTO #t FROM tb
ORDER BY col1,col2
DECLARE @col1 varchar(10),@col2 varchar(100)
UPDATE #t SET
@col2=CASE WHEN @col1=col1 THEN @col2+','+col2 ELSE col2 END,
@col1=col1,
col2=@col2
SELECT * FROM #t
/*--更新处理后的临时表
col1 col2
---------- -------------
a 1
a 1,2
b 1
b 1,2
b 1,2,3
--*/
--得到最终结果
SELECT col1,col2=MAX(col2) FROM #t GROUP BY col1
/*--结果
col1 col2
---------- -----------
a 1,2
b 1,2,3
--*/
--删除测试
DROP TABLE tb,#t
GO
/*==============================================*/--3.3.4.1 每组 <=2 条记录的合并
--处理的数据
CREATE TABLE tb(col1 varchar(10),col2 int)
INSERT tb SELECT 'a',1
UNION ALL SELECT 'a',2
UNION ALL SELECT 'b',1
UNION ALL SELECT 'b',2
UNION ALL SELECT 'c',3--合并处理
SELECT col1,
col2=CAST(MIN(col2) as varchar)
+CASE
WHEN COUNT(*)=1 THEN ''
ELSE ','+CAST(MAX(col2) as varchar)
END
FROM tb
GROUP BY col1
DROP TABLE tb
/*--结果
col1 col2
---------- ----------
a 1,2
b 1,2
c 3
--*/--3.3.4.2 每组 <=3 条记录的合并
--处理的数据
CREATE TABLE tb(col1 varchar(10),col2 int)
INSERT tb SELECT 'a',1
UNION ALL SELECT 'a',2
UNION ALL SELECT 'b',1
UNION ALL SELECT 'b',2
UNION ALL SELECT 'b',3
UNION ALL SELECT 'c',3--合并处理
SELECT col1,
col2=CAST(MIN(col2) as varchar)
+CASE
WHEN COUNT(*)=3 THEN ','
+CAST((SELECT col2 FROM tb WHERE col1=a.col1 AND col2 NOT IN(MAX(a.col2),MIN(a.col2))) as varchar)
ELSE ''
END
+CASE
WHEN COUNT(*)>=2 THEN ','+CAST(MAX(col2) as varchar)
ELSE ''
END
FROM tb a
GROUP BY col1
DROP TABLE tb
/*--结果
col1 col2
---------- ------------
a 1,2
b 1,2,3
c 3
--*/
GO
RETURNS varchar(100)
AS
BEGIN
DECLARE @re varchar(100)
SET @re=''
SELECT @re=@re+','+bj
FROM tb
WHERE kr=@kr and km=@km
RETURN(STUFF(@re,1,1,''))
END
GOselect kr,km,dbo.f_str(kr,km) bj
from tb
group by kr,km
if object_id('tempdb.dbo.#T') is not null drop table #T
create table #T (bj varchar(4),km varchar(2),kr varchar(1))
insert into #T
select '一01','yw','a' union all
select '一01','sx','b' union all
select '一02','yw','a' union all
select '一02','sx','b' union all
select '一03','yw','a' union all
select '一03','sx','c'select kr,km,bjlb=(stuff((select ','+bj from #T where kr=a.kr and km=a.km for xml path('')),1,1,'')) from #T a group by kr,km/*
kr km bjlb
---- ---- --------------
a yw 一01,一02,一03
b sx 一01,一02
c sx 一03
*/
insert fg select '一01','yw','a' union
select '一01','sx','b' union
select '一02','yw','a' union
select '一02','sx','b' union
select '一03','yw','a' union
select '一03','sx','c'
go
CREATE FUNCTION dbo.f_str(@kr varchar(10),@km varchar(10))
RETURNS varchar(100)
AS
BEGIN
DECLARE @re varchar(100)
SET @re=''
SELECT @re=@re+','+bj
FROM fg
WHERE kr=@kr and km=@km
RETURN(STUFF(@re,1,1,''))
END
GOselect kr,km,dbo.f_str(kr,km) bj
from fg
group by kr,kmgodrop table fg
drop function f_str/*
kr km bj
------ ---- --------------------------------------------------
a yw 一01,一02,一03
b sx 一01,一02
c sx 一03(所影响的行数为 3 行)
*/
insert rb select '一01','yw','a' union
select '一01','sx','b' union
select '一02','yw','a' union
select '一02','sx','b' union
select '一03','yw','a' union
select '一03','sx','c'
go
create function f_str(@km varchar(4))
returns varchar(100)
as
begin
declare @s varchar(100)
select @s = isnull(@s+',','') + bj
from rb
where kr = @km
return @s
endgoselect km,kr,dbo.f_str(kr)
from rb
group by km,kr
drop table rb
drop function f_str
/*
km kr
---- ------ -----------------
sx b 一01,一02
sx c 一03
yw a 一01,一02,一03(所影响的行数为 3 行)
*/
谢谢你的回复,不过呢………………你知道
I am very very lazy~~~~
我要稍等下,看看有没有哪位仁兄能完全按我的表重写代码。
要是没有的话,啊,当然………………
if object_id('tempdb.dbo.#T') is not null drop table #T
create table #T (bj varchar(4),km varchar(2),kr varchar(1))
insert into #T
select '一01','yw','a' union all
select '一01','sx','b' union all
select '一02','yw','a' union all
select '一02','sx','b' union all
select '一03','yw','a' union all
select '一03','sx','c'--> 2005
select kr,km,bjlb=(stuff((select ','+bj from #T where kr=a.kr and km=a.km for xml path('')),1,1,'')) from #T a group by kr,km--> 2000declare @Min int, @Max int, @sql varchar(8000)
select top 1 @Min=1, @Max=count(1) from #T group by kr,km order by 2 desc
while @Min<=@Max
begin
set @sql=isnull(@sql+'+','')+'max(case cn when '+ltrim(@Min)+' then bj else '''' end)'
set @Min=@Min+1
end
exec ('select kr,km,bjlb='+@sql+' from (select *,cn=(select count(1) from #T where kr=t.kr and km=t.km and bj<=t.bj) from #T t) a group by kr,km order by 1')/*
kr km bjlb
---- ---- --------------
a yw 一01,一02,一03
b sx 一01,一02
c sx 一03
*/
insert fg select '一01','yw','a' union
select '一01','sx','b' union
select '一02','yw','a' union
select '一02','sx','b' union
select '一03','yw','a' union
select '一03','sx','c'
go
CREATE FUNCTION dbo.f_str(@kr varchar(10),@km varchar(10))
RETURNS varchar(100)
AS
BEGIN
DECLARE @re varchar(100)
SET @re=''
SELECT @re=@re+','+bj
FROM fg
WHERE kr=@kr and km=@km
RETURN(STUFF(@re,1,1,''))
END
GOselect kr,km,dbo.f_str(kr,km) bj
from fg
group by kr,kmgodrop table fg
drop function f_str/*
kr km bj
------ ---- --------------------------------------------------
a yw 一01,一02,一03
b sx 一01,一02
c sx 一03(所影响的行数为 3 行)
*/