When merging Product and ProductCategory to create a single Product table, and you need all rows from Product with matching ProductCategory data, which join configuration should you use?

• A. Inner join
• B. Right outer join
• C. Full outer join
• D. Left outer join

Answer: (D)

The idea is to keep every row from the main table (Product) and bring in matching data from the related table (ProductCategory). A left outer join does exactly that: it returns all products, and for those with a matching category it attaches the category data; for products with no matching category, the category fields appear as NULL.

If you used an inner join, you'd lose products without a category. A right outer join would keep all categories instead of all products. A full outer join would return all products and all categories but also non-matching pairs, which isn’t needed here.

Example pattern: SELECT p.*, c.CategoryName FROM Product p LEFT JOIN ProductCategory c ON p.CategoryID = c.CategoryID.