DATABASE SYSTEM- DATA DEFINITION LANGUAGE

1. Data definition language.
Ms. V.VENNILA MCA., M.Phil..,
Assistant Professor
Bon Secours College for Women, Thanjavur.

2. AGENDA:
• INTRODUCTION
• DATA DEFINATION LAMGUAGE
• TYPES OF DDL AUTHORIZATION
• DDL IN DATA MANIPULATION
• DDL IN RELATIONAL DATABASE
• CONCLUSION

3. INTRODUCTION
• A collection of interrelated data and set of program to access the
data.
• To provide a way to store and retrieve database information
• To keep information about all customers a saving accounts.
• To allow users to manipulate the information.
• File processing system.

4. DATA DEFINITION LANGUAGE
• The database schema by set of definition expressed by a special
language is called data definition language.
• The storage structured and access methods used by the database
system in DDL , is called data storage and definition language.
• The output of the DDL list, placed in the data dictionary which
contains meta data(data about data).

5. TYPES OF DDL AUTHORIZATION
• There are four types of authorization in data definition language.
READ AUTHORIZATION: allow only reading.
INSERT AUTHORIZATION: allow only insertion of new data.
UPDATE AUTHORIZATION: allow modification but not deletion.
DELETE AUTHORIZATION: allow deletion of data.

6. DDL IN DATA MANIPULATION
• Data manipulation language that enables users to access and manipulate data
by the appropriate data model.
• Data definition language allow one to define tables, integretity constrains,
assertions etc.
• There are many types of accesses in data manipulation language.
• Data manipulation language is the mostly in the DDL concept.
• SYNTAX: >create table account(accno char(10), balance integer);

7. DDL IN RELATIONAL DATABASE
• Relational database uses a collection of tables to represent both data
and relationships among those data.
• There are four parts of the relational database,
Tables
Data manipulation language
Data definition language
Database access from application program

8. CONCLUSION
• Data definition language is a standard for commands that define
the different structures in a database
• Data definition language statements create, modify, and remove
database objects such as tables, indexes, and users.
• Common data definition language statements are
CREATE,ALTER, and DROP.