5.1 Overview of SQL Command Types

Level: 5 | Version: v1.1 | Author: Meptrasoft

Overview

SQL commands are used to work with databases in different ways. For easier learning, they are commonly grouped into five categories:

Category	Full Form	Purpose	Main Commands
DDL	Data Definition Language	Manage database structure	`CREATE`, `ALTER`, `DROP`, `TRUNCATE`
DML	Data Manipulation Language	Change data	`INSERT`, `UPDATE`, `DELETE`
DQL	Data Query Language	Retrieve data	`SELECT`
DCL	Data Control Language	Manage permissions	`GRANT`, `REVOKE`
TCL	Transaction Control Language	Manage transactions	`COMMIT`, `ROLLBACK`, `SAVEPOINT`

Think of it as:
DDL → Structure
DML → Data
DQL → Retrieve
DCL → Access
TCL → Transactions

DDL → Defines database structure
DML → Changes stored data
DQL → Retrieves data
DCL → Controls access
TCL → Controls transactions

The next topics explain each category separately in detail.

What are the commonly taught SQL command categories?: DDL, DML, DQL, DCL, and TCL.
What is DDL used for?: Managing database structure.
What is DML used for?: Changing data stored in tables.
What is DQL used for?: Retrieving data, mainly using SELECT.
What is DCL used for?: Managing database permissions and access.
What is TCL used for?: Managing transactions.

Classify the following commands into DDL / DML / DQL / DCL / TCL:

💡 Tip: Test your queries using the in-browser interactive runner above.

DDL → STRUCTURE
DML → DATA
DQL → RETRIEVE
DCL → ACCESS
TCL → TRANSACTION

SQL commands are commonly grouped according to what they do with the database.

End of Overview of SQL Command Types