DML, DDL, DCL and TCL

Structured Query Language (SQL) is a language used by database to perform operations and to create databases. That language has some commands and they are categorized as; DML, DDL, DCL, TCL and for some writers DQL is consideate one of theses category as well.

The following, definitions and examples.

DML – Data Manipulation Language - It is basically used to manipulate data. When it is necessary insert, update or delete data, commands DML are utilized.

DDL – Data Definition Language - It is basically used to manipulate objects.

DCL – Data Control Language - It is basically used to control access and give permissions.

TCL - Transaction Control Language- Commands deals with the transaction within the database.

DQL – Data Query Language - Some people disagree if it should be categorized separated or to be part of DML because the only command of SQL is SELECT.

In the end, this picture below sum up how that categories are divided.