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ER Diagram

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This document discusses E-R diagrams, requirements analysis, structured analysis (SA), object-oriented analysis (OOA), entity types, attributes, and relationships between entities. It also covers different types of relationships such as 1:1, 1:n, m:n, and examples of these relationships.

E-R Diagram#

Requirements Analysis#

  1. Structured Analysis (SA)
  2. Object-Oriented Analysis (OOA)

Screenshot_20220523_213701

  • Entity Type: Box
  • Attribute: Ellipse
  • Relationship: Diamond, and indicate the relationship (1, m, n) on the line connecting the entities

Relationship between two entities#

  1. 1:1
  2. 1
  3. m

Relationship between more than two entities#

  1. One-to-Many (1:n)

Screenshot_20220523_214225

  1. Many-to-Many (m:n

    )

Screenshot_20220523_214415

  1. 1:n
  2. 1:1
  3. 1:1:1

Relationship within a single entity#

  1. 1

Screenshot_20220523_214702

  1. m
    Screenshot_20220523_215709

Example#

Screenshot_20220523_221204

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