DBMS-SQL And PL/SQL- 2.1-Various Database Language -SPPU

Data Definition Language (DDL)

This language allows the users to define data and their relationship to other types of data. It. is used to create data tables, dictionaries, and files within databases.

- The DDL is also used to specify the structure of each table, set of associated values with each attribute, integrity constraints, security and

authorization information for all the tables and •

physical storage structure of all the tables on the disk.

- It takes SQL for instance to categorize the statements that come under DDL.

o To create the database instance-CREATE

o To alter the structure of database - ALTER

o To drop database instances - DROP

o To rename database instances - RENAME

2.3.2 Data Manipulation Language (DML)

- The Data Manipulation Language (DML) is used for accessing and manipulating data in a database. DML provides a set of functionalities to support the basic data manipulation operations on the data stored in the database.

- It allows users to access, insert, update, and delete data from the database.

o To access or read records from the table -

SELECT

o To insert a record into the table - INSERT

o Update the records in the table - UPDATE

o Delete the records from the table - DELETE

Data Control Language (DCL)

Data Control Language (DCL) is used to control the .user access to the database-related elements like tables, views, functions, procedures, and packages.

It provides different levels of access to the objects in the database.

o To grant access to user - G NT

o To revoke access from user-REVOKE,

Grant: GRANT is used to provide privileges to the users on the database objects. The privileges could bethe 

COMMIT Transaction - commits (Save permanently) transactions

ROLLBACK Transaction - ROLLBACK (Cancels. undo) transactions in case of any issue

2.4 SOL Operators

- An operator is a character or reserved word used in SQL statements to perform different operations like arithmetic or comparison.

- Operators are used to specify conditions in an SQL statement and also used to integrate multiple conditions in an SQL statement