WHERE
Keep only the rows that match a condition. It runs before grouping.
Syntax
SELECT … FROM table_name WHERE condition;
- Combine conditions with AND, OR and NOT. Use parentheses when you mix AND and OR.
Example
SELECT order_id, order_date FROM orders WHERE channel = 'online' AND order_date >= '2025-09-10';
Online orders placed from 10 September onwards.
Tables used: orders. Try it in a lesson below.
Common mistakes
- Compare missing values with IS NULL, never with = NULL.
- Text values go in single quotes. Double quotes name columns.