Chapter 6, Problem 1PE

Program Plan Intro

Entity-Relationship diagram:

• Entity-Relationship (ER) diagram is the method to represent the relational database using graphical form.
• This graphical representation shows only primary elements such as records, types, attributes, relationships between entities, and so on.
• The graphical representation of the ER diagram clearly describes the relationship among entities.
• In the diagram, every connector is labeled.
  • On one side it is represented by the value 1, and on the other side it is labeled with the value “M”. This labeling is referred to as “cardinality constraint” of the relationship.

Explanation of Solution

ER diagram for the Car Insurance Company:

Explanation:

In the above ER diagram, “Customer”, “Car”, “Accident”, “Insurance_Policy”, and “Premium_Payment” are the entities.

• The “Customer” entity contains “cust_ID”, “cust_Name”, “cust_Address” and “cust_Phone attributes. Here, “cust_ID” is a primary key.
• The “Car” entity contains “car_Num”, “model”, “make”, “color”, and “year” attributes. Here, “car_Num” is a primary key.
• The “Accident” entity contains “report_ID”, “location”, “date” and “damage_Cost” attributes. Here, “report _ID” is a primary key.
• The “Insurance_Policy” entity contains “policy_Num”, “policy_Name”, and “coverage” attributes. Here, “policy_Num” is a primary key.
• The “Premium_Payment” entity contains “payment_ID”, “payment_Date”, “due_date”, and “amount” attributes. Here, “payment_ID” is a primary key

Relationships between the entities:

• One “Customer” contains many “Car” so here, one-to-many relationship exists and named it as “Owns”.
• One “Car” contains many “Insurance_Policy” so here, one-to-many relationship exists and named it as “Covers”.
• One “Car” meets optional many (zero or many) “Accident” so here, one-to-optional many relationship exists and named it as “Meets”.
• One “Insurance_Policy” contains many “Premium_Payment” so here, one-to-many relationship exists and named it as “Payments”.