Entity-Relationships (ER) Modeling Concepts and Application

Part 2 Assignment: Entity-Relationships (ER) Modeling Concepts and Application

Purpose

This Assignment will assess your comprehension of key database terms, application of foreign and primary key placement, and development of entity-relationships models that match provided database design scenarios.

Assignment
Part 1: Definitions

Define each of the following terms. In addition, provide an example of each term.

Business rule
Entity set (entity type)
Entity instance
Attribute
Relationship
Connectivity
Cardinality constraint
Primary key
Foreign key
Associative entity

Part 2: Business Rules

Please use this four-row format when writing your connectivity-determining business rules.

Figure 1. Publisher Database (ATTACHED)
Figure shows an Entity-Relationship (ER) model with five tables and the connecting relationships. The five tables include: Book, Author, Publisher, Country, and Volume.

Explanation of each row in the 4-row format:
Write the entity pair. Underline and/or bold.
Give one business rule. Indicate the multiplicity of that rule in parentheses.
Give the other business rule. Indicate the multiplicity of that rule in parentheses.
Give the connectivity. (If the connectivity is M:N, give the associative entity name.)

Following is an example of the required four-row format for business rules for a binary relationship for this Assignment.

Example:

Publisher – Book

ONE Publisher may publish MANY Books [M]

ONE Book has ONE Publisher [1]

Publisher 1:M Book.

Complete the same 4-row format for the remaining relationships in the ERD illustrated in Figure 1.

Be sure the connectivity row (row 4) for each 1:M relationship has the correct direction. The rule with the multiplicity “many” will determine the direction. For example, if the rule is: “ONE Publisher may publish MANY Books,” then Publisher is the “1” table and Book is the “M” table, so you would write the connectivity as: Publisher 1:M Books.

Use the four-row format to write the business rules and connectivity for each of the four binary relationships other than Publisher-Book in the enterprise data model pictured above in Figure 1.

Part 3: Primary Key/Foreign Key Placement

The primary key (PK) of a table is often named after the table. Example: ISBN-13 is chosen as the name of the primary key for the Book table; PublisherID is the PK of the Publisher table.

For each entity set in the table below, give the primary key attribute(s) and the foreign key attribute(s) (if any). ***TABLE ATTACHED***

Hint 1 – There may not be a foreign key attribute if the entity is not on the “M” side of a relationship.

Hint 2 – One entity type in the above table is not shown in Figure 1.

Part 4: Entity Relationship Diagram
Update the ERD from Question 2 (Figure 1) to account for the M:N relationship between Book and Author.

Part 5: Entity Relationship Diagram Including Review of Books by Customers Scenario

The report form attached shows the fields to identify the review of books by customers. Follow either the top-down database design or the bottom-up database design approach to extend the ERD from Question 2 (Figure 1). Provide the new ERD. Include a 4–6 sentence paragraph describing how you chose the approach you used to extend the ERD and the process followed.

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