DDL (Data Definition Language)

What
When
Where
Who
Why
How
How many

What is DDL?

DDL stands for Data Definition Language. It is a subset of SQL used to define and manage a database's structure. DDL commands are used to create, modify, and delete objects like tables, indexes, views, and constraints.

What

What is DDL?

DDL stands for Data Definition Language. It is a subset of SQL used to define and manage a database's structure. DDL commands are used to create, modify, and delete objects like tables, indexes, views, and constraints.

When is DDL used?

DDL statements are used to set up and modify a database's structure. They are employed during database creation, table and column changes, constraint definitions, view creation and alteration, and index management.

Where is DDL applied?

DDL statements are executed on the database server through SQL interfaces or management tools provided by the DBMS. They perform operations on the database schema and objects.

Who uses DDL?

DBAs and developers use DDL statements to define and manage the database structure. DBAs handle tasks like creating, maintaining, and modifying the database schema, while developers use DDL to create and modify database objects in their application development process.

Why is DDL important?

DDL is essential for defining and managing a database's structure. It enables the creation and modification of tables, views, indexes, and other objects, ensuring data integrity and efficient data management.

How does DDL work?

DDL commands like CREATE, ALTER, and DROP are used to perform actions on the database schema. For example, CREATE TABLE creates a new table, ALTER TABLE modifies an existing table, and DROP TABLE removes a table from the database.

How many types of DDL commands are there?

There are several types of DDL commands, including:

  • CREATE: Used to create database objects such as tables, views, indexes, etc.
  • ALTER: Used to modify the structure of existing database objects.
  • DROP: Used to remove or delete database objects.
  • TRUNCATE: Used to remove all data from a table.
  • RENAME: Used to rename database objects.
  • COMMENT: Used to add comments to the database objects.