UPDATE
ModificationModifies existing rows in a table based on a condition.
Syntax
UPDATE table SET col1 = val1, col2 = val2 WHERE condition
Example
UPDATE products
SET price = price * 0.9,
updated_at = NOW()
WHERE category = 'clearance';About SQL UPDATE
The UPDATE keyword belongs to the Modification category of SQL statements. Modifies existing rows in a table based on a condition. 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 UPDATE 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 UPDATE: 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.