CREATE TABLE with constraints in SQL
SQL interview exercise on Schema Design, difficulty 2 of 3. Solve it in the editor beside a worked example, or cold in Interview mode with the example hidden; the tests run the moment you do.
Create a reviews table: id (integer primary key), product_id (required, references products), rating (required, only 1 to 5 allowed) and body (optional text). The tests try to insert a good review, a rating of 9 and a missing rating; only the good one may get in.
Each exercise pairs a worked example with a twin problem to solve in a real editor; the tests run the moment you do. Interview mode hides the example: solve it from memory, without the hint or the solution, and it counts as solved cold. Progress is saved in your browser, and in your account if you sign in.