Er diagram in visual paradigm

ERD Diagram Assignment

SECTION 1

Data Fundamentals Overview

Section Beginning (Dark Color Option )

1

Fundamental relationship

Relationship between two entity types

A person, place, or thing “acts” upon something to complete ”x” (i.e. purchase a product)

Binary Relationships

Data Fundamentals Overview

Salesperson

Product

Sells

2

Represents the maximum number of entities that can be involved in a relationship.

One-to-One Binary Relationship

One-to-Many Binary Relationship

Many-to-Many Binary Relationship

Cardinality

Data Fundamentals Overview

3

The minimum number of entity occurrences that can be involved in a relationship.

“inner” symbol on E-R diagram (“outer” symbol is cardinality)

Modality

Data Fundamentals Overview

Everyone order has exactly ONE customer AND Every customer has one or more ORDERS

4

Associate occurrences of an entity type with other occurrences of the same entity type.

Unary Relationships

Data Fundamentals Overview

5

A single occurrence of one entity type can be associated with a single occurrence of the other entity type and vice versa

1:1 Relationships

Data Fundamentals Overview

Student

Student ID #

6

Use “crow’s foot” to represent the multiple association.

“many” = the maximum number of occurrences that can be involved, means a number that can be 1, 2, 3, ... n.

1:M Relationships

Data Fundamentals Overview

Company

Product A

Product B

Product C

7

“Many” can be either an exact number or have a known maximum.

M:M Relationships

Data Fundamentals Overview

Musicians

Albums

Musicians

Musicians

8

Involves three different entity types

Ternary Relationships

Data Fundamentals Overview

9

Describes the relationship between two entities.

Used with many-to-many relationships.

Represented on E-R diagram as an “associative entity”

Intersection Data

Data Fundamentals Overview

10

Entities can have attributes; many-to-many relationships can have attributes.

Many-to-many relationship may be treated similarly to entities in an E-R diagram.

Associative Entity

Data Fundamentals

11

SECTION 2

Data Modeling Creation

Section Beginning (Dark Color Option )

12

A diagramming technique

Diagrams entities (with attributes) and the relationship between the entities.

There are many variations of E-R diagrams in use.

The E-R Diagram

Data Fundamentals Overview

13

Entity Relationship Diagram Basics

Entity type’s attributes are shown below the separator line.

PK and boldface denote the attribute(s) that constitute the entity type’s unique identifier

Rectangular shape

OBJECT = a type of entity

Name of entity is in caps above the separator line.

Data Fundamentals Overview

14

In an ER diagrams, common practice is to a convention that entity type and relationship type names are uppercase letters, attribute names have their initial letter capitalized, and role names are lowercase letter

Data Definition & Naming Conventions

Data Fundamentals Overview

15

SECTION 3

Assignment

Section Beginning (Dark Color Option )

16

Each book has an id, title, publication date, publisher, ISBN, functional category, page count, price (publisher), and product description

There are 3 categories of book: fiction, non-fiction, and specialty

There are 2 categories of music: digital and media-based

An author can write one or more books.

A musician can be a solo artist, part of a group, or both

An author can also be associated with one or more publishers.

A musician/group/act can be associated with one or more music houses

An author’s book can have one or more editions.

A song and or album can have more than one version/edition (i.e. EP, LP, CD, DVD etc)

A publisher can have many authors and many books.

A record company can have many artists associated and many albums associated with it.

A record company can also be the publishing company (i.e. self-publishing)

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Many ISBNs can also be associated with a given publisher but only one ISBN per form of medium (ie the ISBN is the PK no matter what).

An author can write many books.

An artist can write many songs, albums etc.

UCOnline needs to keep track of user ratings for each item sold in the online store (e.g., 1-5 and 1 for ‘Dislike’, to 5, for ‘Awesome!’).

A particular user rates a particular item at a given time.

A user CANNOT rate the same multiple times unless there are multiple editions of the item. Each edition can be rated separately.

Each user who submits a rating will be identified by a unique id and has a name, gender, age, and location. Nothing is anonymous.

There is also a social network between users. Users can send communication requests (i.e. instant messages/emails) to other users. Such requests can be accepted or ignored. Once accepted, the two users are considered ‘book buddies.’ If ignored, the user can send the request again. We want to add a store when the requests were sent (timestamp), the result of the requests and when the request was answered (timestamp).

Tools

Visio

Visual Paradigm Online

SQLDBM

Draw.io

ERDPlus

Lucidchart