1.
Data Modeling
by:
Dr. Bharat V. Chawda
Computer Engineering Department,
BBIT, VVNagar, Gujarat, India
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2.
Overview
 Data Modeling
 Data Objects
 Data Attributes
 Relationships
 Cardinality
 Modality
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3.
Data Modeling
 Def:
 “Process used to define and analyze data
requirements of a software.”
 What?
 Data objects: to be processed by system
 Attributes: that describe data objects
 Relationships: among data objects
 To represent: ER Diagram
 Outcome: Database
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4.
Data Objects
 Def:
 “Any composite data/information that is used
(understood) by a software.”
 Example: Student; Not only student name
 Can be –
 External entity (Emp, Cust, Supp); Thing (Bill, Order)
 A Role (Admin, Manager)
 Organization Unit (Dept); Place (Branch of a Bank)
 Structure (File)
 Data objects are related to each other
 Encapsulates data only; No reference to
Operations
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5.
Attributes
 Def:
 “Properties of data objects”
 Example:
 Student: id, name, add, city, c_no, email
 Can be used to –
 Name an instance of the data object: student name
 Describe the instance: student id, add, city
 Make reference to another instance in another table:
some foreign key (bname in Account table)
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6.
Relationships
 Def:
 “Association among data objects”
 Example:
 An account belongs to a branch, or,
 A branch can have accounts.
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7.
Cardinality
 Concept:
 “Represents no. of occurrences of an object that can be
related to no. of occurrences of another object.”
 Types:
 One-to-One
 One-to-Many, or, Many-to-One
 Many-to-Many
 Notation:
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ACC Belongs BRANCH

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Modality
 Concept:
 “Represents participation of objects into relationship”
 1: Participation in Relationship is Mandatory  Total
 0: Participation in Relationship is Optional  Partial
 Example:
 Customer borrows Loan
 Notation:
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CUSTOMER Borrows Loan

9.
Thank U…!!!
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