AND, OR, NOT

AND requires both conditions, OR either one, NOT flips one. AND binds tighter than OR, so a OR b AND c means a OR (b AND c); use parentheses whenever both appear in one clause, for your reader as much as for the database.

Think of the condition as a question asked of each row: "is this hardware costing under 100, or is it stationery?" Rows answering yes are kept.

SELECT name FROM employees WHERE dept = 'Engineering' AND salary > 7000;

Your task

Show the name, category, and price of products that are either hardware costing less than 100, or anything in the stationery category.

SELECT name, category, price FROM products
WHERE (category = 'hardware' AND price < 100) OR category = 'stationery';