Help with a confusing and advanced query - If Exsists?

Ok,

I need to select a list of products based on a complex criteria. First off, here is a list of the tables I am using and their function.

Dbo.Products – This table holds product names and information.

Dbo.Products_Attributes – This table holds a list of attributes for each product. It has a many to 1 relationship with Products. This table holds only 2 fields – ProductID and AttributeID

Dbo.Customers – This table holds basic customer information and some of the needed criteria for the product search.

Dbo.Customers_Attributes – This table contains a list of attributes that the customer needs in his/her products. This table has a many to 1 relationship with Customers and only has 2 fields, CustomerNum and AttributeID

Dbo.Attributes – This table contains all of the different attributes possible for our products to have. Each can be used by a customer when choosing criteria.

Background: Each attribute is a True / False. Either they want that attribute, or they do not care if they get it or not. This is where the hard part comes in. If a particular attribute is listed as needed in dbo.Customers_Attributes, then I do not want any records pulled from Products that DOES NOT have this attribute. On the other hand, if the attribute is NO listed in the customers_attributes list, it is assumed that the customer wants it. In other words, if there were NO attributes in the customers_attributes list, ALL products would be returned. Attributes listed in the customers_attributes table are "required" (no product will be returned that does not have what is in the list).

I hope I was clear enough… I had to change the table names a functions slightly because of some stupid policy about giving out too much proprietary information here.

If any of you know how to do the above with a subquery of some kind, please let me know.

Dave LarsonI'm not sure that I catch your task properly, but try something like that:

SELECT ProductId, ProductName
FROM dbo.Products
WHERE (NOT (ProductId IN
(SELECT dbo.Products.ProductId
FROM dbo.Products INNER JOIN
dbo.Product_Attributes ON dbo.Products.ProductId = dbo.Product_Attributes.Product
WHERE (dbo.Product_Attributes.Attribute IN
(SELECT dbo.Castomer_Attributes.Attribute
FROM dbo.Castomer_Attributes INNER JOIN
dbo.Customers ON dbo.Castomer_Attributes.Customer = dbo.Customers.CustomerId
WHERE (dbo.Customers.CustomerId = @.CustomerId))))))

where @.CustomerId is a parameter.