NOT

Operator

Negates a condition. Returns true when the condition is false.

Syntax

WHERE NOT condition

Example

SELECT * FROM users
WHERE NOT country = 'US'
AND NOT role = 'admin';

About SQL NOT

The NOT keyword belongs to the Operator category of SQL statements. Negates a condition. Returns true when the condition is false. Understanding this command is essential for any developer working with relational databases like PostgreSQL, MySQL, SQLite, or SQL Server.

SQL (Structured Query Language) is the standard language for managing and querying relational databases. The NOT statement is supported across all major database systems, though specific syntax may vary slightly between PostgreSQL, MySQL, MariaDB, Oracle, SQL Server, and SQLite. Always consult your database's documentation for vendor-specific features and limitations.

Best practices for using NOT: always test queries on a development database before running them in production, use parameterized queries to prevent SQL injection, and leverage EXPLAIN to understand query performance. For complex queries, consider using CTEs (Common Table Expressions) to improve readability and maintainability.

Related SQL Keywords

ANDORWHEREEXISTS