SQL - 3 table mash up (select all left, all right, show status of middle)

Question

I'm stumped on this one. In short, I have 3 tables: Product, Ranging, Account. Ranging is the middle table which is the link between Product and Account.

e.g. a ranging record links to 1 account and 1 product. Products can have many rangings, so can Accounts.

What i'm trying to end up with is 3 columns: 1 = Product Name, 2 = Account Name, 3 = Ranging (exist (yes/no). That's easy, but the tricky bit is that I want to show EVERY Account under each product.

i.e. if I have PROD 1, 2 and 3 and account A, B and C. I want to see:

• Prod 1 - Account A - Ranging Status (yes/no)
• Prod 1 - Account B - Ranging Status (yes/no)
• Prod 1 - Account C - Ranging Status (yes/no)
• Prod 2 - Account A - Ranging Status (yes/no)
• Prod 2 - Account B - Ranging Status (yes/no)
• Prod 2 - Account C - Ranging Status (yes/no)
• Prod 3 - Account A - Ranging Status (yes/no)
• Prod 3 - Account B - Ranging Status (yes/no)
• Prod 3 - Account C - Ranging Status (yes/no)

The account, product and ranging all have ID's that are linked (PK, FK etc)

I've tried a cross join with a inner join to no avail. Appreciate the help!

Answer 1

Are you looking for this?

SELECT q.product_name, q.account_name,
       CASE WHEN r.product_id IS NULL THEN 'no' ELSE 'yes' END status
  FROM 
(
  SELECT product_id, product_name, account_id, account_name
    FROM product p CROSS JOIN account a
) q LEFT JOIN ranging r
    ON q.product_id = r.product_id
   AND q.account_id = r.account_id
 ORDER BY q.product_name, q.account_name

Sample output:

| PRODUCT_NAME | ACCOUNT_NAME | STATUS |
----------------------------------------
|    Product 1 |    Account A |    yes |
|    Product 1 |    Account B |     no |
|    Product 1 |    Account C |    yes |
|    Product 2 |    Account A |    yes |
|    Product 2 |    Account B |     no |
|    Product 2 |    Account C |     no |
|    Product 3 |    Account A |     no |
|    Product 3 |    Account B |     no |
|    Product 3 |    Account C |     no |

Here is SQLFiddle demo

Answer 2

you need cross join to do this:

  select
      p.name as product_name,
      a.name as account_name,
      case when r.product_id is not null then 'yes' else 'no' end as Ranging
  from product as p
      cross join account as a
      left outer join ranging as r on r.product_id = p.id and r.account_id = a.id
  order by p.name, a.name