What is DDL, DML, DCL? What are their differences and examples of commands?

DDL (Data Definition Language) — a language for defining data. It is used to create and modify the structure of a database. Examples of commands:

• CREATE TABLE
• ALTER TABLE
• DROP TABLE

DML (Data Manipulation Language) — a language for manipulating data. It allows adding, modifying, deleting, and retrieving data. Examples of commands:

• SELECT
• INSERT
• UPDATE
• DELETE

DCL (Data Control Language) — a language for managing access and permissions. Examples of commands:

• GRANT (to grant permissions)
• REVOKE (to revoke permissions)

Differences:

• DDL works with the database structure.
• DML works with the content of tables.
• DCL manages user rights and security.