Question

I have 3 tables

1) tblPurchaser having 2 columns:

PurchaserId   PurchaserName
1             A1
2             A2
3             A3

2) tblCar having 2 columns:

CarId   Carname
11      C1
12      C2
13      C3
14      C4

And the last is a junction table tblInformation where the information about those persons are given who has purchased cars.

PurchaserId  CarId
1            11
1            12
2            11
2            13

Now I need to write a set based query where I can be able to obtain the information of those cars which has not been purchased by the persons

Desired Output

PurchaserId  CarId
1            13
1            14
2            12
2            14      
3            11
3            12
3            13
3            14 

Note: This is a real time problem which I am implementing in my project. Because of privacy of company, I have changed the tables and information. But my situation is something similar
Please help me

Edited

So far I have written this query:

SELECT 1 as purchaserid,carid from tblcar
where carid not in (select carid from tblinformation where purchaserid = 1)
union all
SELECT 2 as purchaserid,carid from tblcar 
where carid not in (select carid from tblinformation where purchaserid = 2)
union all
SELECT 3 as purchaserid,carid from tblcar 
where carid not in (select carid from tblinformation where purchaserid = 3)

But as you can make out that i am hardcoding the purchaserid’s. And also in real time I will not know how many id’s will be there. So everything has to be done at runtime.

Please helpenter code here

Answer 1

Try this

 select pur.PurchaserId, car.CarId
   from tblPurchaser pur, tblCar car
  where not exists (select 1 from tblInformation  where PurchaserId = pur. PurchaserId and CarId = car. CarId) 
 order by pur.PurchaserId;