Quick Notes Two categories of SQL statement s: Data Definition Language (DDL) used to describe a database, to define its structure, to create its objects and to create the table's sub-objects. The following list provides some examples of types of DDL statements: Creating tables (CREATE command) Modifying the structure of a table (ALTER command) without deleting and re-creating it, such as adding columns, removing columns or changing column definitions (for example, length or default values) Removing objects (such as tables) from the database (DROP command) Partitioning tables (PARTITION command) Data Manipulation Language (DML) used to control the information contained within the database. The following lists provides some examples of types of DML statements: Adding records to a table (INSERT command) Modifying information in a table (UPDATE command) Removing records from a table (DELETE command)