Data Definition Language (DDL) is a subset of SQL. Its primary function is to create, modify, and delete database structures but not data. The commands in DDL are: CREATE, DROP, ALTER, TRUNCATE and RENAME Remember: In DDL operations, COMMIT and ROLLBACK statement cannot be performed because the MySQL engine automatically commits the changes.In SQL DDL commands are used to create and modify the structure of a database and database objects. These commands are CREATE, DROP, ALTER, TRUNCATE, and RENAME