Tag Archives: Data definition language

SQL Structure

SQL Structure SQL Structure : The SQL language comprised of following parts: Data Definition Language (DDL) We know that RDBMS uses tables and the SQL-DDL provides commands for defining relation schema, deleting relations, creating indices, and modifying relation schema. DDL commands CREATE, ALTER and DROP used for creating, altering and removing relational schema. The SQL DDL includes …

Data definition language

Data definition language Data definition language – The SQL DDL allows the specification of not only a relations, but also information about each relation, including The schema for each relation The domain of value associated with each attribute The Integrity constraints The set of indices to be maintained for each relation The security and authorization …