database management system

1. Submitted to :- submitted by :-
Mohanjeet sir Vasu Vashisht

2. Database
A database is collection of interrelated
and organized data. A database is
interrelated collections of many different
type of tables

3. The external or view level is the highest level of
abstraction of database. It provides a window on the
conceptual view, which allows the user to see only the
data of interest to them. The user can be either an
application program or an end user. There can be many
external views as any number of external schema can be
defined and they can overlap each other. It consist of the
definition of logical records and relationships in the
external view. It also contains the method of deriving the
objects such as entities, attributes and relationships in the
external view from the conceptual view.

4. The conceptual level presents a logical view of the entire database as a unified
whole. It allows the user to bring all the data in the database together and see it
in a consistent manner. Hence , there is only one conceptual schema per
database. The first stage in the design of a database is to define the conceptual
view, and a DBMS provides a data definition language for this purpose. it
describes all the records and relationships included in the database.
The data definition language used to create the conceptual level must not specify
any physical storage considerations that should be handled by the physical level.
It does not provide any storage or acess details, but defines the information
content only.

5. The collection of files permanently stored on secondary storage
devices is known as the physical database. The physical or
internal level is the one closest to the physical storage, and it
provide a low level description of the physical database, and an
interface between the operating system file system and the record
structures used in higher level of abstraction. It is at this level that
record types and methods of storage are defined, as well as how
stored fields are represented, what physical sequence the stored
records are in, and what other physical structures exist.

6. Employee 1
Eid
Name
dept id
Salary
city
Employee 2
Eid
Name
dept id
Salary
city
Employee 3
Eid
Name
dept id
Salary
city
Dept id
D name
region
R id
R name
Department table
region table
logical data
independence
Physical data
independence
external
level
conceptual
level
Internal
level

7. departmentstudent
Academic
program
Roll
no
name
address
semester
HOD
Dept
name
DEPT
NAME
DURATION
COURS
ES
PROG
CODE
PROG
NAME
REGISTER
COURSE
COURS
E NO
TITLE OF
COURSE
REGISTER
COURSE
CREDIT
ALLOTED
COURS
E
NODES
GNATIO
N
DEPARTMENT
EMPLOYEE
CODE
NAME

8. STUDENT
ROLL NO – 101
NAME – VASU
ADDRESS – KHANNA
SEMESTER - 4
EXTERNAL
VIEW
STUDENT
ROLL NO – NUMBER
NAME – TEXT
ADDRESS – TEXT
SEMESTER - NUMBER
CONCEPTUAL
VIEW
ROLL NO – 101
NAME – VASU
ADDRESS – KHANNA
SEMESTER - 4
DEPARTMENT – CS
DEPT CODE 1011
HOD - RAJEEV
EMP NAME- SUMIT
DEPT – C.S
DESIGNATION - TEACHER
NAME -MANAGEMENT
CODE 1033
DURATION -4
COURSE - BCA
INTERNAL
LEVEL

9. CONSTRAINTS
ROLL NO – INT
NAME – NOT BE NULL
ADDRESS – KHANNA OR CHANDIGARH
OR LUDHIANA
SEMESTER- INTEGER
SALARY- NOT <5000

10. HIERARCHIAL MODEL
student
name
semester
ADDRES
S
department
HOD
Dept
name
DEPT
NAME
DESIGNA
TIONDEPARTMEN
T
EMPLOYEE
CODE
name
DURATION
COURS
ESPROG
CODE
PROG
NAME
ACADEMIC
PROGRAM
COURS
E NOTITLE OF
COURSE
REGISTER
COURSE
CREDIT
ALLOTED

11. THANKS
FOR YOUR
COOPERATION