A select query selecting a select statement

Question

I don't even know if I am doing this query the right way. There is a Sandwiches table that has some 7 fields and 2 of them are comboboxes (Type and Bread).

So I made a query that combines all of the comboboxes values into one query, like this:

SELECT TypesAndBreads.TBName, TypesAndBreads.Type
FROM (SELECT [Sandwiches Types].[Sandwich Type] As TBName, "Sandwich Type" As Type
    FROM [Sandwiches Types]
UNION ALL
    SELECT Breads.Bread As TBName, "Bread" As Type 
    FROM Breads)  AS TypesAndBreads;

I get the flat values of the tables now I want to count all the sandwiches under each TypesAndBreads.TBName. I have this, just to make sure it works with all the Sandwiches:

SELECT TypesAndBread.Type, TypesAndBread.TBName,
       (SELECT Count(Sandwiches.[SandwichID]) As SandwichCount
        FROM Sandwiches) As SandwichCount
FROM TypesAndBread;

But I want to reference the current Type and TBName inside the subquery. Something like this:

SELECT TypesAndBread.Type, TypesAndBread.TBName,
       (SELECT Count(Sandwiches.[SandwichID]) As SandwichCount
        FROM Sandwiches
        WHERE Sandwiches.[TypesAndBread.Type] = Sandwiches.[TypesAndBread.TBName]) As SandwichCount
FROM TypesAndBread;

But of course this doesn't work. I didn't think it will, just thought of giving it a try. I was thinking of maybe constructing the query with VBA when they open the Report that this query is going to be based of.

So I guess my question is: Is there a way to reference the current selected fields in a subquery? Or is there a different way to approach this?

Thanks for the help

EDIT: My table structure is like this:

Sandwiches's fields

| SandwichID | Name | Date Added | Chef | Sandwich Type | Bread | Reviewed By |

where Sandwich Type and Bread are Lookup fields for these tables:

Sandwiches Types's fields

| Sandwich Type |

Breads's fields

| Bread |

The TypesAndBreads query combined the Sandwiches Types and Breads tables, but the reason for that is so that I can get the count of all the sandwiches that have that Type or bread. A result like this:

+=============================================+
|      Type     |    TBName   | SandwichCount |
+=============================================+
| Sandwich Type | Turkey Club |            10 |
| Bread         | Italian     |             5 |
| Bread         | Garlic      |             8 |
+---------------------------------------------+

the example result's first row basicly says there are 10 sandwiches in record with the Sandwich Type field equal to Turkey Club.

I hope that explains it better.

Answer 1

Not sure if Access supports it, but in most engines (including SQL Server) this is called a correlated subquery and works fine:

SELECT  TypesAndBread.Type, TypesAndBread.TBName,
        (
        SELECT  Count(Sandwiches.[SandwichID]) As SandwichCount
        FROM    Sandwiches
        WHERE   (Type = 'Sandwich Type' AND Sandwiches.Type = TypesAndBread.TBName)
                OR (Type = 'Bread' AND Sandwiches.Bread = TypesAndBread.TBName)
        ) As SandwichCount
FROM    TypesAndBread

This can be made more efficient by indexing Type and Bread and distributing the subqueries over the UNION:

SELECT  [Sandwiches Types].[Sandwich Type] As TBName, "Sandwich Type" As Type,
        (
        SELECT  COUNT(*) As SandwichCount
        FROM    Sandwiches
        WHERE   Sandwiches.Type = [Sandwiches Types].[Sandwich Type]
        )
FROM    [Sandwiches Types]
UNION ALL
SELECT  [Breads].[Bread] As TBName, "Bread" As Type,
        (
        SELECT  COUNT(*) As SandwichCount
        FROM    Sandwiches
        WHERE   Sandwiches.Bread = [Breads].[Bread]
        )
FROM    [Breads]