SUM

Aggregate

Calculates the total sum of a numeric column.

Syntax

SUM(col)

Example

SELECT department,
       SUM(salary) as total_payroll
FROM employees
GROUP BY department;

About SQL SUM

The SUM keyword belongs to the Aggregate category of SQL statements. Calculates the total sum of a numeric column. 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 SUM 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 SUM: 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

COUNTAVGMINMAX