Case-Based Critical Thinking Questions
Case 9-3
Taylor manages a database for a regional hardware enterprise with 10 stores in 2 states. The hardware store wholesales to contractors. The database includes these tables (among others): tblContractor, tblProducts, tblBilling, tblInvoices.
-Taylor wants to create a query that shows all contractors and identifies invoices assigned to those contractors. However, he also wants to see contractors who might not have an invoice assigned for this billing period. What type of join between tables will give Taylor the desired results?
A)inner join
B)outer join
C)self-join
D)many-to-many

Question

Case-Based Critical Thinking Questions
Case 9-3
Taylor manages a database for a regional hardware enterprise with 10 stores in 2 states.  The hardware store wholesales to contractors. The database includes these tables (among others): tblContractor, tblProducts, tblBilling, tblInvoices.
-Taylor wants to create a query that shows all contractors and identifies invoices assigned to those contractors.  However, he also wants to see contractors who might not have an invoice assigned for this billing period.  What type of join between tables will give Taylor the desired results?
A)inner join
B)outer join
C)self-join
D)many-to-many

Quizplus · Accepted Answer

An outer join will give Taylor the desired results because it will show all contractors, including those who do not have an invoice assigned for the billing period. Specifically, a left outer join on tblContractor and tblInvoices (using the contractor ID as the join criterion) will accomplish this.