REPLACE
FunctionReplaces all occurrences of a substring within a string.
Syntax
REPLACE(string, old, new)
Example
SELECT REPLACE(phone, '-', '') as clean_phone FROM contacts;
About SQL REPLACE
The REPLACE keyword belongs to the Function category of SQL statements. Replaces all occurrences of a substring within a string. 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 REPLACE 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 REPLACE: 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.