INTERVAL

Data Type

Represents a time duration. Used for date arithmetic and time-based queries.

Syntax

timestamp + INTERVAL 'duration'

Example

SELECT * FROM sessions
WHERE created_at > NOW() - INTERVAL '30 days';

SELECT NOW() + INTERVAL '2 hours' as future;

About SQL INTERVAL

The INTERVAL keyword belongs to the Data Type category of SQL statements. Represents a time duration. Used for date arithmetic and time-based queries. 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 INTERVAL 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 INTERVAL: 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

NOWDATE_TRUNCEXTRACTBETWEEN