Question

Explain the following SQL commands
1 DDL
2 DML
3 TCL​

Answer 1

Explanation:

DDL (Data Definition Language):

DDL or Data Definition Language actually consists of the SQL commands that can be used to define the database schema. It simply deals with descriptions of the database schema and is used to create and modify the structure of database objects in the database.DDL is a set of SQL commands used to create, modify, and delete database structures but not data. These commands are normally not used by a general user, who should be accessing the database via an application.

List of DDL commands:

CREATE: This command is used to create the database or its objects (like table, index, function, views, store procedure, and triggers).

DROP: This command is used to delete objects from the database.

ALTER: This is used to alter the structure of the database.

TRUNCATE: This is used to remove all records from a table, including all spaces allocated for the records are removed.

COMMENT: This is used to add comments to the data dictionary.

RENAME:

This is used to rename an object existing in the database.

DML(Data Manipulation Language):

The SQL commands that deals with the manipulation of data present in the database belong to DML or Data Manipulation Language and this includes most of the SQL statements. It is the component of the SQL statement that controls access to data and to the database. Basically, DCL statements are grouped with DML statements.

List of DML commands:

INSERT : It is used to insert data into a table.

UPDATE: It is used to update existing data within a table.

DELETE : It is used to delete records from a database table.

TCL commands are meant to handle database transactions

TCL Commands - Commit, Rollback and Savepoint | Studytonight

hope it helps

Answer 2

ANSWER:

1) Data definition language is a syntax for creating and modifying database objects such as tables, indices, and users.

2) Data manipulation language is a computer programming language used for adding, deleting, and modifying data in a database.

3) Telephone communication limited is a high-level, general-purpose, interpreted, dynamic programming language.

EXPLANATION:

Hope it helps!!