sql查詢與加入的幫助或子查詢

Question

返回輸出我有兩個表

Table1        Table2 
id  Name      id table1id  Name 
1  A      1  1   a 
2  B      2  1   aa 
3  C      3  1   aaa 
           4  2   b 
           5  2   bb 

我想輸出 名1名2

A   a 
      aa 
      aaa 
B   b 
      bb 

Answer 1

試試這個：

Declare @Table1 table 
(id int ,name varchar(10)) 

Insert into @Table1 
values 
(1,'A'), 
(2,'B'), 
(3,'C') 


Declare @Table2 table 
(id int,tableid int ,name varchar(10)) 

Insert into @Table2 
values 
(2, 1,'aa'), 
(3, 1,'aaa'), 
(4, 2 ,'b'), 
(5,2,'bb') 


;With cte(Name1,Name2,rn) as 
(Select t1.name ,t2.name, 
    row_number() over (partition by t1.name order by t1.id) as rn 
    from @table1 as t1 inner join @Table2 as T2 
    on t2.tableid=t1.id 
) 
Select case when rn=1 then name1 else '' end as c1, 
name2 
from cte