SQL operators for arithmetic, comparison and logic
The arithmetic, comparison and logical operators you use to build conditions and expressions in SQL.
SQL provides various operators for calculations, comparisons, and combining conditions.
Arithmetic Operators
| Operator | Description | Example |
|---|---|---|
| + | Addition | price + tax |
| - | Subtraction | total - discount |
| * | Multiplication | price * quantity |
| / | Division | total / count |
| % | Modulo (remainder) | id % 2 |
-- Calculate order totals
SELECT
product_name,
price,
quantity,
price * quantity AS subtotal,
price * quantity * 0.1 AS tax,
price * quantity * 1.1 AS total
FROM order_items;
-- Find even/odd IDs
SELECT * FROM users WHERE id % 2 = 0; -- Even IDsComparison Operators
| Operator | Meaning | Example |
|---|---|---|
| = | Equal to | status = 'active' |
| != or <> | Not equal to | role != 'admin' |
| < | Less than | age < 18 |
| > | Greater than | price > 100 |
| <= | Less than or equal | quantity <= 0 |
| >= | Greater than or equal | rating >= 4 |
Logical Operators
-- AND: Both conditions must be true SELECT * FROM products WHERE price > 50 AND category = 'Electronics'; -- OR: Either condition can be true SELECT * FROM users WHERE role = 'admin' OR role = 'moderator'; -- NOT: Negates a condition SELECT * FROM orders WHERE NOT status = 'cancelled'; -- Combining with parentheses (IMPORTANT!) SELECT * FROM products WHERE category = 'Electronics' AND (price < 100 OR on_sale = TRUE);
Tip: AND has higher precedence than OR. Use parentheses to make your intent clear!