我有2个表,table1和table2
table1里面有一个关键字列“ID”
table2里面有另外一个列“ID_1”和它对应例如
teble1
ID name
001 张三
002 李四table2
ID ID_1 item Num
001 001 苹果 1
002 001 梨 2
003 002 桃 1
004 002 香蕉 3name item
张三 苹果+梨2
李四 桃+香蕉3注意,查询结果中,如果Num是1就不显示,不是1的就显示
table1里面有一个关键字列“ID”
table2里面有另外一个列“ID_1”和它对应例如
teble1
ID name
001 张三
002 李四table2
ID ID_1 item Num
001 001 苹果 1
002 001 梨 2
003 002 桃 1
004 002 香蕉 3name item
张三 苹果+梨2
李四 桃+香蕉3注意,查询结果中,如果Num是1就不显示,不是1的就显示
标题:按某字段合并字符串之一(简单合并)
作者:爱新觉罗.毓华(十八年风雨,守得冰山雪莲花开)
时间:2008-11-06
地点:广东深圳描述:将如下形式的数据按id字段合并value字段。
id value
----- ------
1 aa
1 bb
2 aaa
2 bbb
2 ccc
需要得到结果:
id value
------ -----------
1 aa,bb
2 aaa,bbb,ccc
即:group by id, 求 value 的和(字符串相加)
*/
--1、sql2000中只能用自定义的函数解决
create table tb(id int, value varchar(10))
insert into tb values(1, 'aa')
insert into tb values(1, 'bb')
insert into tb values(2, 'aaa')
insert into tb values(2, 'bbb')
insert into tb values(2, 'ccc')
gocreate function dbo.f_str(@id varchar(10)) returns varchar(1000)
as
begin
declare @str varchar(1000)
select @str = isnull(@str + ',' , '') + cast(value as varchar) from tb where id = @id
return @str
end
go--调用函数
select id , value = dbo.f_str(id) from tb group by iddrop function dbo.f_str
drop table tb
--2、sql2005中的方法
create table tb(id int, value varchar(10))
insert into tb values(1, 'aa')
insert into tb values(1, 'bb')
insert into tb values(2, 'aaa')
insert into tb values(2, 'bbb')
insert into tb values(2, 'ccc')
goselect id, [value] = stuff((select ',' + [value] from tb t where id = tb.id for xml path('')) , 1 , 1 , '')
from tb
group by iddrop table tb
--3、使用游标合并数据
create table tb(id int, value varchar(10))
insert into tb values(1, 'aa')
insert into tb values(1, 'bb')
insert into tb values(2, 'aaa')
insert into tb values(2, 'bbb')
insert into tb values(2, 'ccc')
go
declare @t table(id int,value varchar(100))--定义结果集表变量
--定义游标并进行合并处理
declare my_cursor cursor local for
select id , value from tb
declare @id_old int , @id int , @value varchar(10) , @s varchar(100)
open my_cursor
fetch my_cursor into @id , @value
select @id_old = @id , @s=''
while @@FETCH_STATUS = 0
begin
if @id = @id_old
select @s = @s + ',' + cast(@value as varchar)
else
begin
insert @t values(@id_old , stuff(@s,1,1,''))
select @s = ',' + cast(@value as varchar) , @id_old = @id
end
fetch my_cursor into @id , @value
END
insert @t values(@id_old , stuff(@s,1,1,''))
close my_cursor
deallocate my_cursorselect * from @t
drop table tb
if object_id('[table1]') is not null drop table [table1]
go
create table [table1]([ID] varchar(3),[name] varchar(4))
insert [table1]
select '001','张三' union all
select '002','李四'
go
if object_id('[table2]') is not null drop table [table2]
go
create table [table2]([ID] varchar(3),[ID_1] varchar(3),[item] varchar(4),[Num] int)
insert [table2]
select '001','001','苹果',1 union all
select '002','001','梨',2 union all
select '003','002','桃',1 union all
select '004','002','香蕉',3
go
---查询---
select
a.name,
item=stuff((select '+'+item+case when num=1 then '' else ltrim(num) end from table2 b where a.id=b.id_1 for xml path('')),1,1,'')
from
table1 a---结果---
name item
---- ------------------
李四 桃+香蕉3
张三 苹果+梨2(2 行受影响)
if object_id('[table1]') is not null drop table [table1]
go
create table [table1]([ID] varchar(3),[name] varchar(4))
insert [table1]
select '001','张三' union all
select '002','李四'
go
if object_id('[table2]') is not null drop table [table2]
go
create table [table2]([ID] varchar(3),[ID_1] varchar(3),[item] varchar(4),[Num] int)
insert [table2]
select '001','001','苹果',1 union all
select '002','001','梨',2 union all
select '003','002','桃',1 union all
select '004','002','香蕉',3
go
create function dbo.f_str(@name varchar(10)) returns varchar(1000)
as
begin
declare @str varchar(1000)
select @str = isnull(@str + '+' , '') + cast(item as varchar) from (select name,item from table1 a,(select id_1,(+item+ case when num=1 then '' else ltrim(num) end) as 'item' from table1 a ,table2 b where a.id=b.id_1) as d where a.id=d.id_1) as c where name = @name
return @str
end
goselect name , item = dbo.f_str(name) from (select name,item from table1 a,(select id_1,(+item+ case when num=1 then '' else ltrim(num) end) as 'item' from table1 a ,table2 b where a.id=b.id_1) as d where a.id=d.id_1) as c group by namedrop function dbo.f_strdrop table tb