QUIZ SHOW ppt BASED ON CPP DBMS DISCRETE MATHEMATICS AND GENERAL KNOWLEDGE
Ppt of dbms e r features
-
Upload
nirali-akabari -
Category
Engineering
-
view
138 -
download
4
Transcript of Ppt of dbms e r features
![Page 1: Ppt of dbms e r features](https://reader036.fdocuments.us/reader036/viewer/2022073102/55a6957d1a28abe1208b45dd/html5/thumbnails/1.jpg)
GANDHINAGAR INSTITUTE OF
TECHNOLGY
Department of Information Technology
E-R FeaturesGroup ID: IT_A1_10
Students Names: Akabari Nirali (130120116002)
Akanksha Sharma (130120116003)
Guided By: Prof. Anirudhdha Nayak
Database Management System(2130703)
![Page 2: Ppt of dbms e r features](https://reader036.fdocuments.us/reader036/viewer/2022073102/55a6957d1a28abe1208b45dd/html5/thumbnails/2.jpg)
Presentation outlines:
E-R concept
Specialization
Generalization
Aggregation
E-R diagram notation for representing
specialization
E-R diagram with redundant
relationship
E-R diagram with Aggregation
![Page 3: Ppt of dbms e r features](https://reader036.fdocuments.us/reader036/viewer/2022073102/55a6957d1a28abe1208b45dd/html5/thumbnails/3.jpg)
Basic E-R concepts
The original concept of the entity-
relationship model was given by Chen in
1976.
High level conceptual(logical) data
model.
Widely used in database design to
represent a conceptual schema.
A conceptual schema represented by the
E-R model is called an E-R schema.
![Page 4: Ppt of dbms e r features](https://reader036.fdocuments.us/reader036/viewer/2022073102/55a6957d1a28abe1208b45dd/html5/thumbnails/4.jpg)
The basic notation used in E-R
diagram are illustrated below:
An entity set
An Attribute
A Relationship set
Link between an
entity set &
attribute
![Page 5: Ppt of dbms e r features](https://reader036.fdocuments.us/reader036/viewer/2022073102/55a6957d1a28abe1208b45dd/html5/thumbnails/5.jpg)
Specialization
Specialization is the process of
defining sub-class based on some
distinguishing characteristics.
In other words, specialization identifies
the sub-sets possesses some
attributes
Specialization is a top-down process
to define super-class/sub-class
relationships.
![Page 6: Ppt of dbms e r features](https://reader036.fdocuments.us/reader036/viewer/2022073102/55a6957d1a28abe1208b45dd/html5/thumbnails/6.jpg)
![Page 7: Ppt of dbms e r features](https://reader036.fdocuments.us/reader036/viewer/2022073102/55a6957d1a28abe1208b45dd/html5/thumbnails/7.jpg)
Generalization
Generalization is the process of
defining a super-class from sub-
classes based on some common
characteristics.
In other words, generalization
identifies a super-class from different
entity-sets(or sub-classes).
Generalization is a bottom-up process
to define super-class/sub-class
relation.
![Page 8: Ppt of dbms e r features](https://reader036.fdocuments.us/reader036/viewer/2022073102/55a6957d1a28abe1208b45dd/html5/thumbnails/8.jpg)
A bottom-up design process – combine
a number of entity sets that share the
same features into a higher-level entity
set.
Specialization and generalization are
simple inversions of each other; they
are represented in an E-R diagram in
the same way.
The terms specialization and
generalization are used
interchangeably.
![Page 9: Ppt of dbms e r features](https://reader036.fdocuments.us/reader036/viewer/2022073102/55a6957d1a28abe1208b45dd/html5/thumbnails/9.jpg)
![Page 10: Ppt of dbms e r features](https://reader036.fdocuments.us/reader036/viewer/2022073102/55a6957d1a28abe1208b45dd/html5/thumbnails/10.jpg)
Aggregation
Aggregation is an abstraction through
which relationships are treated as
higher level entities.
Thus, for our example, we regard the
relationship set works on as a higher-
level entity set called works on.
Such an entity set is treated in the same
manner as is any other entity set.
Figure shows a notation for aggregation
commonly used to represent this
situation.
![Page 11: Ppt of dbms e r features](https://reader036.fdocuments.us/reader036/viewer/2022073102/55a6957d1a28abe1208b45dd/html5/thumbnails/11.jpg)
E-R Diagram With
Aggregation
![Page 12: Ppt of dbms e r features](https://reader036.fdocuments.us/reader036/viewer/2022073102/55a6957d1a28abe1208b45dd/html5/thumbnails/12.jpg)
E-R Diagram With
Redundant Relationships
![Page 13: Ppt of dbms e r features](https://reader036.fdocuments.us/reader036/viewer/2022073102/55a6957d1a28abe1208b45dd/html5/thumbnails/13.jpg)