SQL Operators

SQL Operators

SQL operators are used to perform comparisons, logical operations, and calculations in queries.

Comparison Operators

• = Equal
• <> or != Not equal
• > Greater than
• < Less than
• >= Greater than or equal
• <= Less than or equal

SELECT name
FROM customers
WHERE country = 'USA';

Logical Operators

• AND
• OR
• NOT

SELECT name
FROM customers
WHERE country = 'USA' AND status = 'active';

Arithmetic Operators

• + Addition
• - Subtraction
• * Multiplication
• / Division
• % Modulus (database-specific)

SELECT price, quantity, price * quantity AS total
FROM order_items;

Special Operators

• IN
• BETWEEN
• LIKE
• IS NULL
• EXISTS

SELECT name
FROM customers
WHERE country IN ('USA', 'Canada');

Bitwise Operators (Database-Specific)

Some database systems support bitwise operators such as &, |, ^. Support depends on the database engine.

Operator Precedence

SQL follows a logical order of precedence. For example, AND is evaluated before OR. Use parentheses to control evaluation order.

SELECT name
FROM customers
WHERE country = 'USA' AND (status = 'active' OR status = 'trial');

Common Mistakes

• Forgetting parentheses when mixing AND and OR
• Using = NULL instead of IS NULL
• Assuming operator precedence incorrectly

Next Step

You have completed the core SQL Tutorial. Continue with the SQL Database section to learn how to create and manage databases and tables.