Logical Data Modeling - Relationship Representation / Implementation / Visualisation

1 - About

A relationship can be described/implemented by:

3 - Type

3.1 - Function

A relationship can be represented as a function

Example with a three element (ternary) relationship: <MATH> y = f(x,z) </MATH>

3.2 - Operator

A binary relationship can be represented as an operator <MATH> y <= x </MATH>

3.3 - Set of tuples

A relationship can be represented as a set of tuples of every entity identifier.

For instance, the relation less than or equal (⇐) on the set of integers {1, 2, 3} is the set of tuple:

<1, 1>
<1, 2>
<1, 3>
<2, 2>
<2, 3>
<3, 3>

The set of tuples can physically be implemented as:

3.4 - Graphic

The relationship less than or equal (y⇐x) can be represented in the set <math>R</math> against <math>R^2</math> as the below gray area:

3.5 - Association

The below diagram defines two associations:

  • a book is published by one publisher and a publisher publishes many books
  • a book is written by many author and a author writes many books

Data Science
Data Analysis
Data Science
Linear Algebra Mathematics

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