What is a Data Definition Language?

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Data definition language (DDL) is the subset of the database which defines the data structure of the database in the initial stage when the database is about to be created. It consists of the following commands: CREATE, ALTER and DELETE database objects such as schema, tables, view, sequence, etc.

In SQL, Data Definition Language (DDL) is a subset of SQL statements used to define, manage, and manipulate the structure of a database. DDL statements are responsible for creating, altering, and deleting database objects, such as tables, indexes, and views. Some common DDL statements include:

  1. CREATE: Used to create a new database object, such as a table, index, or view.
  2. ALTER: Used to modify the structure of an existing database object, such as adding or removing columns from a table.
  3. DROP: Used to delete a database object, such as a table, index, or view.

In summary, DDL is concerned with the schema and structure of the database. It allows you to define and manage the tables and other objects that make up the database, specifying their attributes, relationships, and constraints.