需要幫助建立與TSQL

Question

查詢我有以下結構和數據表：

ID_A | ID_B 
A  1 
A  2 
B  1 
B  2 
C  1 
C  3 
D  1 
D  2 
D  3 

我需要找到不同的集B的存在對於給出的ID。在這個例子中，結果將是：

1. 1,2
2. 1,3
3. 1,2,3

如果我能拿到票也將是巨大的：

1. 1,2- [2]
2. 1,3 [1]
3. 1， 2,3 [1]

我希望問題很明顯。謝謝！

Answer 1

SQL Fiddle

MS SQL Server 2012的架構設置：

create table YourTable 
(
    ID_A char(1), 
    ID_B int 
) 

insert into YourTable values 
('A',  1), 
('A',  2), 
('B',  1), 
('B',  2), 
('C',  1), 
('C',  3), 
('D',  1), 
('D',  2), 
('D',  3) 

查詢1：

select T.ID_B, 
     count(*) as C 
from 
    (
    select T1.ID_A, 
     (
     select ','+cast(T2.ID_B as varchar(10)) 
     from YourTable as T2 
     where T2.ID_A = T1.ID_A 
     order by T2.ID_B 
     for xml path(''), type 
     ).value('substring(text()[1], 2)', 'varchar(max)') as ID_B 
    from YourTable as T1 
    group by T1.ID_A 
) as T 
group by T.ID_B 

Results：

| ID_B | C | 
------------- 
| 1,2 | 2 | 
| 1,2,3 | 1 | 
| 1,3 | 1 |