DELETE

Modification

Removes rows from a table based on a condition. Use with caution — always include a WHERE clause.

Syntax

DELETE FROM table WHERE condition

Example

DELETE FROM sessions
WHERE expires_at < NOW();

About SQL DELETE

The DELETE keyword belongs to the Modification category of SQL statements. Removes rows from a table based on a condition. Use with caution — always include a WHERE clause. 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 DELETE 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 DELETE: 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.

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