SQL · Chapter 5 of 42

SQL WHERE

WHERE filters rows using conditions. Combine multiple conditions with AND, OR and NOT.

Operators: `=`, `<>` (not equal), `>`, `<`, `>=`, `<=`, `BETWEEN`, `LIKE`, `IN`, `IS NULL`.

Syntax

SELECT ... FROM table WHERE condition;

Combining conditions

Use AND / OR / NOT. Parentheses control precedence.

SQL uses `<>` (standard) or `!=` (many dialects) for 'not equal'.

Example 1 (sql)

SELECT * FROM users WHERE age >= 18 AND country = 'India';

Output

name | age | country
Ana  | 25  | India

Two conditions combined with AND.

Example 2 (sql)

SELECT * FROM products WHERE price BETWEEN 100 AND 500;

Output

product   | price
Book      | 250
Headphone | 499

BETWEEN is inclusive on both ends.

💡 Note: `WHERE col = NULL` NEVER matches. Use `WHERE col IS NULL` instead.