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Entity-Relationship diagrams for Case Study 2

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This is the second of three case studies that are used to guide the reader through the six steps outlined in Six-Step Relational Database Design™. Some of the outputs of the six step database design process are depicted here. Get a copy of Six-Step Relational Database Design™ to get the details of all six steps.

Scenario

Below is the scenario for Case Study 2 as described in Six-Step Relational Database Design™:

The owners of a small computer repair shop would like to keep track of the repair jobs for computers they repair, the items used for each repair job, the labor costs for each repair job, the repairmen performing each repair job, and the total cost of each repair job.

When customers bring their computers in to be repaired, they make a deposit on the repair job and are given a date to return and uplift their computer. Repairmen then perform repairs on the customers’ computers based on the repair job, and detail the labor costs and the items used for each repair job.

When customers return they pay the total cost of the repair job less the deposit, collect a receipt for their payment, and uplift the repaired computer using this payment receipt.

 

Entity-Relationship diagrams

Below is the Simplified Entity-Relationship diagram that is output from Step 3 of the six step database design process as described in Six-Step Relational Database Design™:

Case Study 2 simplified E-R diagram

 

Below is the Detailed Entity-Relationship diagram that is output from Step 5 of the six step database design process as described in Six-Step Relational Database Design™:

Case Study 2 detailed E-R diagram

 

View the resulting Crow's Foot Relational-Model diagram for Case Study 2.