What is DDL? Make a list of commands with short description used in DDL

Ans: Data Definition Language that is abbreviated as DDL is a computer language for defining data structures. The phrase was first introduced in relation to the Codasyl database model in which the schema of the database was written in a Data Definition Language explaining the records, fields, and "sets" making up the user Data Model.

  List of DDL commands:

  (a) To define a table/ relation

  CREATE TABLE ------

  (b) To eliminate table/relation definition

DROP TABLE ----

  (iii) To alter the definition of an existing table

  ALTER TABLE-------