SQL Tutorial · SQL Basics · Lesson 5 of 36

SQL AND, OR, NOT

Combine conditions and control precedence with parentheses.

AND and OR

AND — both conditions must be true.
OR — at least one must be true.

Example 1Try it yourself

SELECT name, price, stock FROM products WHERE price < 50 AND stock > 20;
SELECT name, country FROM customers WHERE country = 'Japan' OR country = 'Netherlands';

Output

name | price | stock
SQL for Beginners | 29.99 | 40
Wireless Mouse | 24.99 | 60
USB-C Hub | 39.95 | 30
Coffee Mug | 12 | 100
Rubber Duck | 5.5 | 200

name | country
Guido van Rossum | Netherlands
Yukihiro Matsumoto | Japan

Parentheses matter

AND is evaluated before OR. Use parentheses to say what you mean:

Example 2Try it yourself

-- Electronics OR books, and only if in stock:
SELECT name, category_id, stock FROM products
WHERE (category_id = 1 OR category_id = 2) AND stock > 0;

Output

name | category_id | stock
SQL for Beginners | 1 | 40
Clean Code | 1 | 15
Mechanical Keyboard | 2 | 25
Wireless Mouse | 2 | 60
4K Monitor | 2 | 8
USB-C Hub | 2 | 30

NOT

NOT negates a condition: NOT status = 'cancelled', NOT IN (...), NOT LIKE ..., IS NOT NULL.

Example 3Try it yourself

SELECT order_id, status FROM orders WHERE NOT status IN ('delivered', 'cancelled');

Output

order_id | status
4 | shipped
8 | shipped
9 | pending
11 | pending

Test yourself

Which is evaluated first without parentheses: AND or OR?

AND
OR
Whichever comes first
Neither

Show answer

Answer: AND