Question

Ok, so i’m trying to write a complex query (at least complex to me) and need some pro help. This is my database setup:

Table: MakeList

| MakeListId | Make     |
| 1          | Acura    |
| 2          | Chevy    |
| 3          | Pontiac  |
| 4          | Scion    |
| 5          | Toyota   |

Table: CustomerMake

| CustomerMakeId | CustomerId | _Descriptor |
| 1              | 123        | Acura       |
| 2              | 124        | Chevy       |
| 3              | 125        | Pontiac     |
| 4              | 126        | Scion       |
| 5              | 127        | Toyota      |
| 6              | 128        | Acura       |
| 7              | 129        | Chevy       |
| 8              | 130        | Pontiac     |
| 9              | 131        | Scion       |
| 10             | 132        | Toyota      |

Table: Customer

| CustomerId | StatusId |
| 123        | 1        |
| 124        | 1        |
| 125        | 1        |
| 126        | 2        |
| 127        | 1        |
| 128        | 1        |
| 129        | 2        |
| 130        | 1        |
| 131        | 1        |
| 132        | 1        |

What i am trying to end up with is this…

Desired Result Set:

| Make    | CustomerId|
| Acura   | 123       |
| Chevy   | 124       |
| Pontiac | 125       |
| Scion   | 131       |
| Toyota  | 127       |

I am wanting a list of unique Makes with one active (StatusId = 1) CustomerId to go with it. I’m assuming i’ll have to do some GROUP BYs and JOINS but i haven’t been able to figure it out. Any help would be greatly appreciated. Let me know if i haven’t given enough info for my question. Thanks!

UPDATE: The script doesn’t have to be performant – it will be used one time for testing purposes.

Answer 1

Something like this:

select cm._Descriptor,
       min(cu.customerid)
from CustomerMake cm
  join Customer cu on cuo.CustomerId  = cm.CustomerId and cu.StatusId = 1
group by cm._Descriptor

I left out the MakeList table as it seems unnecessary because you are storing the full make name as _Descriptorin the CustomerMake table anyway (so the question is what is the MakeList table for? Why don’t you store a FK to it in the CustomerMake table?)