This document presents an overview of data models. It defines a data model as how the logical structure of a database is modeled, introducing abstraction in a DBMS. Several types of data models are described, including hierarchical, network, relational, entity-relationship, object-oriented, document, entity-attribute-value, star schema, and object-relational models. The entity-relationship model is explained in more detail, noting that it is based on entities, attributes, and relationships between entities. Entities represent real-world objects and are described by attributes, while relationships define associations between entities.

1. Data Model
Presentation By:- Sumit Rana
BCA (2015-18)

2. A Three-dimensional Representation Of A Person Or Thing Or
Of A Proposed Structure, Typically On A Smaller Scale Than
The Original.
What is a Model ?

3. What is Data Model?
• Data models define how the logical structure of a database is
modeled.
• Data Models are fundamental entities to introduce abstraction in a
DBMS.
• Data models define how data is connected to each other and how
they are processed and stored inside the system.

4. Types of Data Models
• Hierarchical Model
• Network Model
• Relational Model
• Entity-relationship model
• Object-oriented database model
• Document model
• Entity-attribute-value model
• Star schema
• The object-relational model, which combines the two that make up
its name

5. Hierarchical Model
• In this model each entity has
only one parent but can have
several children . At the top of
hierarchy there is only one entity
which is called Root.

6. Network Model
• In the network model, entities
are organized in a graph, in
which some entities can be
accessed through several path

7. Relational Model
• In this model, data is organized
in two-dimesional tables
called relations. The tables or
relation are related to each
other.
• The most common model, the
relational model sorts data into
tables, also known as relations,
each of which consists of
columns and rows.

8. Entity-Relationship Model
• Entity-Relationship (ER) Model is
based on the idea of real-world
entities and relationships among
them. While preparing real-
world scenario into the database
model, the ER Model creates
entity set, relationship set,
general attributes and
constraints.

9. ER Model is based on −
•Entities
•Attributes
•Relationships

10. Entities
• An entity can be a real-world object, that can be easily identifiable.
• For example, in a school database, students, teachers, classes, and
courses offered can be considered as entities. All these entities have
some attributes or properties that give them their identity.

11. Attributes
• Entities are represented by means of their properties,
called attributes. All attributes have values.
• For example, a student entity may have name, class, and age as
attributes.

12. Relationships
• The association among entities is called a relationship.
• For example, an employee works_at a department, a
student enrolls in a course. Here, Works_at and Enrolls are called
relationships.

13. Sources
• www.lucidchart.com
• www.tutorialspoint.com
• www.studytonight.com

14. Any Questions?
In Any Thing I Explained

15. Thanks You
Presentation By:- Sumit Rana
BCA (2015-18)