DDL, DML, DCL and TCL Commands in MySQL Explained

SQL commands are grouped into four families based on what they do. This classification is a guaranteed interview question and a useful mental model for organising everything you learn about SQL.

Key Points

• DDL (Data Definition Language): CREATE, ALTER, DROP, TRUNCATE — defines structure
• DML (Data Manipulation Language): SELECT, INSERT, UPDATE, DELETE — works with data
• DCL (Data Control Language): GRANT, REVOKE — manages permissions
• TCL (Transaction Control Language): COMMIT, ROLLBACK, SAVEPOINT — manages transactions
• DDL statements auto-commit in MySQL; DML changes can be rolled back
• Analysts mostly live in DML; DBAs handle DDL and DCL