juniorSQL
What is a WHERE clause?
Updated May 17, 2026
Short answer
WHERE filters rows based on conditions.
Deep explanation
The WHERE clause restricts query results by evaluating conditions on each row before grouping or aggregation.
Real-world example
Filtering active customers only.
Common mistakes
- Using WHERE instead of HAVING for aggregates.
Follow-up questions
- Can WHERE use multiple conditions?
- Does WHERE run before GROUP BY?