Question

Let’s say I’ve got typical many-to-many relationship with three tables.

---------
--boxes--
---------
id  name
---------
1   Green Box
2   Red Box
3   Yellow Box

----------
--fruits--
----------
id  name
----------
id  name
1   apple
2   orange

--------------
--fruitboxes--
--------------
boxID  fruitID
--------------
1      1
1      2
2      1
2      2
3      1

I want to create a view that would result in

--------------------------
--------boxes view--------
--------------------------
id  name            fruits
--------------------------
1   Green Box       apple,orange
2   Red Box         apple,orange
3   Yellow Box      apple

I’m using a ms SQL. Any ideas how to do this?

thanks

Answer 1

select
  b.id,
  b.name,
  stuff((select ','+f.name
         from fruits as f 
           inner join fruitboxes as fb
             on f.id = fb.fruitID
         where fb.boxID = b.id
         for xml path(''), type).value('.', 'nvarchar(max)'), 1, 1, '') as Fruits
from boxes as b

Test it here: https://data.stackexchange.com/stackoverflow/q/101351/concatenate-strings

Fruit ID’s instead of name

select
  b.id,
  b.name,
  stuff((select ','+cast(fb.fruitID as varchar(10))
         from fruitboxes as fb
         where fb.boxID = b.id
         for xml path('')), 1, 1, '') as Fruits
from boxes as b