DATE_TRUNC

Function

Truncates a timestamp to a specified precision (year, month, day, hour, etc.).

Syntax

DATE_TRUNC('precision', timestamp)

Example

SELECT DATE_TRUNC('month', created_at) as month,
       COUNT(*) as signups
FROM users
GROUP BY month
ORDER BY month;

About SQL DATE_TRUNC

The DATE_TRUNC keyword belongs to the Function category of SQL statements. Truncates a timestamp to a specified precision (year, month, day, hour, etc.). 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 DATE_TRUNC 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 DATE_TRUNC: 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

NOWEXTRACTINTERVAL