標題:按某字段合并字符串之一(簡單合并)
描述:將如下形式的數據按id字段合并value字段。
id value
----- ------
1 aa
1 bb
2 aaa
2 bbb
2 ccc
需要得到結果:
id value
------ -----------
1 aa,bb
2 aaa,bbb,ccc
即:group by id, 求 value 的和(字符串相加)
1、sql2000中只能用自定義的函數解決
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 int) returns varchar(100)asbegin declare @str varchar(1000) set @str='' select @str=@str+''+cast(value as varchar) from tb where id = @id set @str=right(@str , len(@str) - 1) return @strendgo--調用函數select id , value = dbo.f_str(id) from tb group by iddrop function dbo.f_strdrop 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、使用游標合并數據
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')godeclare @t table(id int,value varchar(100))--定義結果集表變量--定義游標并進行合并處理declare my_cursor cursor local forselect id , value from tbdeclare @id_old int , @id int , @value varchar(10) , @s varchar(100)open my_cursor fetch my_cursor into @id , @valueselect @id_old = @id , @s=''while @@FETCH_STATUS = 0begin 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_cursor select * from @tdrop table tb
以上就是關于分組字符合并SQL語句的介紹。希望對大家有所幫助。
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