Question

I have two tables: Customers and Addresses. There can only be 1 customer record, but a customer may have multiple addresses. Each address has true/false field called “active”.

I’m trying to design a query that selects any customers that don’t have an active address. So customers with address records that are all marked “active = false”, or have no address records at all.

I’m working in Access for this, so the SQL needs to be MS friendly. However I am interested to know the general SQL technique to do this kind of selection.

Edit:
Table Structure

Customers

CustomerID, CustomerName, CustomerDoB

Addresses

AddressID, AddressName, AddressPostcode, CustomerID, Active

Answer 1

This should point you in the right direction, without the table schema I’ve made some assumptions:

SELECT * FROM Customers
WHERE ID Not In (SELECT CustomerID FROM Addresses WHERE Active = -1)

This assumes an ID in the customer table and a CustomerID in the addresses table