Mapping cardinality in e r model

1. Pundra University of Science & Technology
Rangpur Road, Gokul, Bogura
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Welcome To My Presentation
Name: Md. Soumik Ahmmed
Department: Computer Science & Engineering
Course Title: Database Management System
Course Code: CSE 311
18 June 2019 1/9

2. Presentation topic:
Mapping Cardinality in E-R Model
18 June 2019
Mapping Cardinality in E-R Model

3. Mapping Cardinality
 Mapping cardinality or cardinality ratios express the
number of entities to switch another entity can be
associated via a relationship set.
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Mapping Cardinality in E-R Model

4. Types of Mapping Cardinality
 For a binary relationship set the mapping cardinality must
be one of the following types:
1.One to one
2.One to many
3.Many to one
4.Many to many
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Mapping Cardinality in E-R Model

5. Mapping Cardinality in E-R Model
One-to-one relationship:
An entity in A is associated with at most
(only) one entity in B is associated with at
most (only) one entity in A.
A customer is connected with only
one loan using the relationship
borrower and a loan is connected
with only one customer using
borrower.
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6. Mapping Cardinality in E-R Model
One-to-Many relationship:
An entity in A is associated with any
number (zero or more) of entities in
Band an entity in B is associated with at
most one (only) entity in A.
In the one to many relationship a
loan is connected with only one
customer using borrower and a
customer is connected with more
than one loans using borrower.
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Mapping Cardinality in E-R Model

7. Mapping Cardinality in E-R Model
Many-to-one relationship:
An entity in A is associated with at
most (only) one entity in B and an
entity in B is associated with any
number (zero or more) of entities in A.
In a many-to-one relationship a
loan is connected with more than
one customer using borrower and
a customer is connected with only
one loan using borrower.
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Mapping Cardinality in E-R Model

8. Mapping Cardinality in E-R Model
Many-to-many relationship:
An entity in A is associated with any number
(zero or more) of entities in Band an entity in
B is associated with any number (zero or
more) of entities in A.
A customer is connected with
more than one loan using
borrower and a loan is
connected with more than one
customer using borrower.
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Mapping Cardinality in E-R Model

9. Thank You
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10. Thank You
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