What is DDL , DML , DCL & TCL

DDL , DML , DCL & TCL are categories of SQL statements also called SQL Languages . They define different areas of SQL which are involved in maintaining database management systems.  Welcome to the SQL Beginners Guide series’ latest article.  We will discuss what is DDL , DML , DCL & TCL and other types and what they do . However , before we move forward. In case you need to check other articles.
Following are the most recent articles

  1. What is SQL ?
  2. MS SQL Installation Step By Step
  3. SQL Select Query
  4. Basic SQL Queries & Commands

Reason for referring you to the previous articles is very simple. This is a series and they are being composed in order . Therefore , this order will help you in developing a better understanding for SQL query development .
SQL commands have following categories


Types of SQL Statements/SQL Commands

  • DML  Data Manipulation Language
  • DDL   Data Definition Language
  • DCL   Data Control Language
  • TCL   Transaction Control Language

Let’s do it people , time to discuss them .

DML  ( Data Manipulation Language )

Remember , CRUD Operations ? The basic SQL queries we use to work with the data in table . It can be as simple as retrieving information from table  , inserting , deleting or update.
SELECT – Retrieves data from tables
INSERT – Inserts data into tables
UPDATE– Update data in tables.
DELETE – Delete data or objects
Previous article , has these SQL queries for practice. In case , you’re interested.

DDL ( Data Definition Language )

Statements that are used to change the state of database objects such as table , schema etc.
CREATE – Create the database objects
ALTER – Can you guess? Yes , Alter the already defined values. Can be datatypes of columns or names of the objects
DROP -Delete existing object from database
TRUNCATE – Also delete the existing from database but to the point that it cannot be restored because no log maintenance for this operation unlike others.

DCL  ( Data Control Language )

Statements that are used to manage and control the access of users on database objects
GRANT – allow user acces to read/write on certain database objects
REVOKE – removes user access from read/write permission on database objects.

TCL ( Transaction Control Language )

SQL Statements that allows you to control and manage transactions to maintain the integrity of data within SQL statements.
BEGIN Transaction – opens a transaction
COMMIT Transaction – commits a transaction
ROLLBACK Transaction – ROLLBACK a transaction in case of any error.

In future , we are planning to write on Concurrency Control where you will see a good use of the TCL Statements. Therefore , my recommendation is to subscribe us and follow us for the latest articles.
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Happy Learning!

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