看懂這個,就會做了:--函數,合並字符串欄位
--測試數據
/*
CREATE table person_info(dept_name varchar(10),position_name varchar(10),person_name varchar(10))
INSERT INTO person_info
SELECT '資訊部','軟件編碼員','小李'
UNION ALL SELECT '資訊部','軟件編碼員','小王'
UNION ALL SELECT '行政部','秘書','小芳'
*/
--合並函數
CREATE FUNCTION FunMergeCharField(@vchA varchar(10),@vchB varchar(10))
RETURNS varchar(8000)
AS
BEGIN
DECLARE @r varchar(8000)
SET @r=''
SELECT @r=@r+','+person_name FROM person_info WHERE dept_name=@vchA and position_name=@vchB
RETURN(substring(@r,2,8000))
END
GO
--删除测试
DROP TABLE person_info
DROP FUNCTION FunMergeCharField--調用
SELECT dept_name,position_name,在職人員=dbo.FunMergeCharField(dept_name,position_name)
FROM person_info
GROUP BY dept_name,position_name
go
--測試數據
/*
CREATE table person_info(dept_name varchar(10),position_name varchar(10),person_name varchar(10))
INSERT INTO person_info
SELECT '資訊部','軟件編碼員','小李'
UNION ALL SELECT '資訊部','軟件編碼員','小王'
UNION ALL SELECT '行政部','秘書','小芳'
*/
--合並函數
CREATE FUNCTION FunMergeCharField(@vchA varchar(10),@vchB varchar(10))
RETURNS varchar(8000)
AS
BEGIN
DECLARE @r varchar(8000)
SET @r=''
SELECT @r=@r+','+person_name FROM person_info WHERE dept_name=@vchA and position_name=@vchB
RETURN(substring(@r,2,8000))
END
GO
--删除测试
DROP TABLE person_info
DROP FUNCTION FunMergeCharField--調用
SELECT dept_name,position_name,在職人員=dbo.FunMergeCharField(dept_name,position_name)
FROM person_info
GROUP BY dept_name,position_name
go
--調用
SELECT dept_name,position_name,在職人員=dbo.FunMergeCharField(dept_name,position_name)
FROM person_info
GROUP BY dept_name,position_name
go
--返回結果
------------------------------------------------------------------
行政部 秘書 小芳
資訊部 軟件編碼員 小李,小王樓主可稍做修改
select Name,Category,aa=cast('' as varchar) into #t
from tablea order by Categorydeclare @Category int,@a varchar(8000)
update #t set @a=case @Category when Category then @a+','+rtrim(name) else rtrim(name) end
,aa=@a,@Category=Categoryselect name=max(aa),Category from #t group by Categorydrop table #t
这条语句为什么能把“小李,小王”循环取出来,它有循环语句的功能吗,为什么?帮我解释一下好吗?