Data Control Language - DCL

Data Control Language (DCL) is a subset of SQL that focuses on managing access rights and permissions within a database. DCL commands are used to control who can do what in the database.

Main DCL Commands:

Command	Description
`GRANT`	Gives a user specific privileges (e.g., to read or modify data)
`REVOKE`	Removes previously granted privileges from a user

GRANT SELECT, INSERT ON Customers TO User123;
REVOKE INSERT ON Customers FROM User123;

Common Privileges:

SELECT – Read data
INSERT – Add new data
UPDATE – Modify existing data
DELETE – Remove data
ALL – Grant all available privileges

Key Characteristics:

DCL handles security and access control in the database.
Typically used by a database administrator (DBA).
Permissions can be granted at the table, column, or database level.
DCL operations are often transaction-dependent, requiring a COMMIT to take effect.

Comparison with Other SQL Subsets:

DDL (Data Definition Language) – Defines the database structure (e.g., tables)
DML (Data Manipulation Language) – Works with the data itself (e.g., insert or update)
TCL (Transaction Control Language) – Manages transactions (COMMIT, ROLLBACK)
DCL (Data Control Language) – Manages permissions and user access