連接後連接行值

Question

如何在連接Table1和Table2後連接行值。

表1：

----- 
Col1  
------ 
    1  
    2  

表2：

----------------- 
Col1   Col2 
----------------- 
1    A 
1    B 
1    C 
2    D 
2    E 
2    F 

所需的結果：

----------------- 
Col1   Col2 
----------------- 
1   A,B,C 
2   D,E,F 

Answer 1

嘗試這種情況：

create table #table1(
    col1 int 
) 
create table #table2(
    col1 int, 
    col2 char(1), 
) 
insert into #table1 
select 1 union all 
select 2 

insert into #table2 
select 1, 'A' union all 
select 1, 'B' union all 
select 1, 'C' union all 
select 2, 'D' union all 
select 2, 'E' union all 
select 2, 'F' 


select 
    col1, 
    col2 = 
     stuff((
      select 
       ', ' + t2.col2 
      from #table2 t2 
      where 
       t2.col1 = t1.col1 
      group by t2.col2 
      for xml path(''), type).value('.', 'varchar(max)' 
     ), 1, 2, '') 
from #table1 t1 

drop table #table1 
drop table #table2 

Answer 2

Mysql：

SELECT group_concat(table2.col2) FROM 
    table2 JOIN table1 ON table1.col1 = table2.col1 
GROUP BY table2.col1 

Answer 3

您可以使用光標作爲以下鱈魚。

檢查語法只

create table #Desired_Result(col1 int,col2 varchar(20)) 
DECLARE cur cursor FAST_FORWARD READ_ONLY 
FOR 
SELECT col1,col2 

DECLARE @d int 
declare @l varchar(20) 

declare @str1 varchar(30)='' 
declare @str2 varchar(30)='' 
OPEN cur 
FETCH NEXT FROM cur INTO @d,@l 
WHILE @@FETCH_STATUS=0 
BEGIN 
if @d=1 
set @str1=@str1+@l+',' 
else 
if @d=2 
set @str2=@str2+@l+',' 
FETCH NEXT FROM cur INTO @d,@l 
END 
@str1=substring(@str1,1,len(@str1)-1) 
@str2=substring(@str2,1,len(@str2)-1) 
insert into #Desired_Result values (col1,col2)(1,@str1) 
insert into #Desired_Result values (col1,col2)(2,@str2) 

select * from #Desired_Result 

Close cur 
DEALLOCATE cur