Database Languages

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Database Languages

Database languages are used to create and maintain database on computer. There is large number of database languages like Oracle, MS- Access, dbase, FoxPro, etc.

SQL statements commonly used in Oracle and MSA Access can be categorized as data definition languages (DDL), data control language (DCL), and data manipulation language (DML).

1. Data Definition Languages (DDL): - It is a language that allows the users to define data and their relationship to other types of data. It is mainly used to create files, databases, dictionary and tables within databases.

It is also used to specify the structure of each table, set of associated values with each attribute, integrity constraints, security and authorization information for each table and physical storage structure of each table on the disk.

S.No.

Need And Usage

The SQL DDL Statement

1

Create schema objects

CREATE

2

Alter schema objects

ALTER

3

Delete schema objects

DROP

4

Rename schema objects

RENAME


2. Data Manipulation language (DML): - It is a language that provides a set of operations to support the basic data manipulation operations on the data held in the databases. It allows users to insert, update, delete and retrieve data from the table. The part of DML that involves data retrieval is called a query language.

The following table gives an overview about the usage of DML statements: -

S.No.

Need And Usage

The SQL DDL Statement

1

Remove rows from tables or views

DELETE

2

Add new rows of data into table or view

INSERT

3

Retrieve data from one or more tables

SELECT

4

Change columns values in existing rows of a table or view

UPDATE

3. Data Control Language (DCL): - DCL statements control access to data and the database using statements such as GRANT and REVOKE. A privilege can either be granted to a user with the help of GRANT statement. The privileges assigned can be SELECT, ALTER, DELETE,EXECUTE, INSERT, INDEX etc. in addition to granting of privileges , you can also revoke it by using REVOKE command.

The following tables give an overview about the usage of DCL statements in SQL: -

S.No

Need And Usage

The SQL DDL Statement

1

Grant and take away privileges and roles

GRANT and REVOKE

2

Add a comment to the data dictionary

COMMENT

This Post has 3 Comments Add your own!
Shoofi - September 4, 2015 at 1:36 AM

Thanks for sharing such a great information about DBMS..
شوفي

atit280 - February 17, 2016 at 4:18 AM

I like this thank dear

atit280 - February 17, 2016 at 4:20 AM

I like this thank dear

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