Data, Information & Knowledge Database DBMS Types of Models E-R Model.
All data models in dbms
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All Data models in
DBMS
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Overview
• Data
• Information
• Database
• Data Model
Types of Data Model
1. Record Base model
• Relationship model
• Network Model
• Hierarchical Model
2.Entity Relationship Model
3.Object-Oriented Model
A data is known as the row fact which is stored in computers memory and used by the user as the output.
Example-21.
Data
InformationCollection of data its called information.
Example-House no 21C-S-1,Sch No 78 Indore
DatabaseA collection of inter related data its called database.
Data Model A data model is a collection of concepts that can be used to describe the structure of a database.
Types of Data Models
1.Record Base model
Relational mode
Network Model
Hierarchical Model
Types of Data Models
1.Record Base model • A record based data model is used to specify the overall logical structure of the database.
• Each record type defines a fixed no. of fields having a fixed length.
Relational model
• In the relational model, data is organized in two-dimensional tables called relations.
Relations
A relation appears as a two-dimensional table.
No Course-Name Unit
CIS15 Intro to C 5
CIS17 Intro to Java 5
CIS19 UNIX 4
CIS51 Networking 5
Attributes
Tuples
• Attributes.
Each column in a relation is called an attribute.
Relations
• Tuples
Each row in a relation is called a tuple. A tuple defines a collection of attribute values.
Network ModelIn the network model, the entities are organized in a graph, in which some entities can be accessed through several paths
No Name ID Name Course
No Name Unit ID Name
DEPARTMENT
COURSES
STUDENTS
PROFESSORS
Hierarchical Model
The hierarchical data model organizes data in a tree structure
PROFESSORS
No Name
ID Name CourseNo Name Unit
ID Name
DEPARTMENT
COURSES STUDENTS
Hierarchical Model
2.Entity Relationship Model
• The E-R (entity-relationship) data model views the real world as a set of basic objects (entities) and relationships among these objects
ER Model Basics•Entity•Entity Set•Attributes•Relationship
Entity
• entity is a thing in the real world with an independent existance. and entity set is collection or set all entities of a particular entity type at any point of time.