Designing relational databases to satisfy business rule
Project allows students to show their skills in the area of designing relational databases to satisfy specific business rules and requirements. Deliverables for this project include an Entity Relationship Diagram and detailed documentation describing the database design and structure.
In this project you will be provided the set of specifications to create an entity-relationship diagram and design accompanying table layout using sound relational modeling concepts and practices. Relationships among the entities and the attributes for the entities will be identified and described. This database will provide the foundation for the follow-on project. The following paragraphs provide the background and summary of the business requirements.
You are a database consultant with Ace Software, Inc. and have been assigned to develop the database for the Mom and Pop Johnson video store in town. Mom and Pop have been keeping their records of videos and DVDs purchased from distributors and rented to customers in stacks of invoices and piles of rental forms for years. They have lastly decided to automate their record keeping with a relational database.
You sit down with Mom and Pop to talk about their business, and watch their operation for about a week. You find out quickly that the video and a DVD are both copies of a movie kept in the separate plastic case which is rented out. They have many copies of each movie they rent; hence there are many videos and DVDs for each movie title. You learn that in their inventory they have several thousand videos and DVDs, which they get wholesale from about a half dozen distributors. Video and DVD prices to them are based on the quantity of their shipment and the past business they have done with each company.
Price of a DVD for a movie may be different than the price of a video for the same movie, even from the same distributor. Each distributor provides different types of movies (e.g., suspense, horror, mystery, comedy, etc.). Single distributor might provide several different types of movies in both video and DVD format. It is possible to get the same movie from multiple distributors, and at different wholesale prices.
All video and DVD has a unique identification number which Mom and Pop assign in their inventory, in addition to the distributor's serial number for the item. Each movie also has a unique identification number Mom and Pop assign in addition to the title, and any movie IDs the distributors use in their electronic catalogs. Distributors give electronic catalogs to Mom and Pop and the information from these catalogs must be included in the database.
Mom and Pop need to record when a video or DVD is rented, when a video or DVD is returned, and all customer charges such as late and damaged fees, failure to rewind fees, and taxes. They need a report of which videos are returned late because there are standard and late charges. On occasion there are discount prices for certain movies or types of movies. Customers want to rent movies based on actors or actresses, running length, type of movie, rating, year released, the director, and the academy awards won (by the movie, the actors, the actresses and/or the directors). Customers also want to know how many videos they have rented in the last month, year, and so forth. Mom and Pop need to keep only basic information on customers in their database, such as name, address, telephone numbers, etc.
There should be no limit to the number of video and/or DVD copies of a movie which Mom and Pop can have in their inventory. Video/DVD ID numbers, movie ID numbers, and distributor ID numbers for videos, DVDs, and movies are all different. Also, each movie should be able to have an unlimited number of actors, actresses, directors, and academy awards (i.e., Oscars). Other types of awards (e.g., Golden Globe, People's Choice, etc.) are not of interest for this application. Rental of equipment, sale of videos, DVDs, popcorn, etc., is not to be kept in the database.
Using this information, you must provide the following in the submission:
1) Determine and list your entities. Explain fully the relationships among entities via pairs of sentences which specify two components of the total relationship in both directions between the entities. Relationships may be unary, binary, or ternary with respect to entities. You must not have any many-to-many relationships.
2) Begin the database logical design by identifying entities, relationships between entities, and entities' attributes as we have done in this course. Sketch ERD by hand or a drawing program (e.g., Visio, PPT, SQL Modeler …) on one single 8-1/2" x 11" page (8-1/2" x 14" maximum), labeled "Mom and Pop Johnson Video Store Database E/R Diagram." ERD should not have any many-to-many relationships between entities. Ensure that all relationships between entities are one-to-many to facilitate the construction of relational database tables.
3) Complete logical database design and start physical database design by creating metadata (i.e. documentation) which describes the table(s) created from each entity and the column(s) created from each attribute in the ERD. Attributes must be self-describing. Particular attention will be given to proper specification of all primary key (via "PK") and foreign key (via "FK") columns in the table layouts. These must match your ERD exactly. Begin these descriptions on a page labelled "Proposed Database Tables and Columns based on E/R Diagram." All tables should be 3rd Normal Form. Point out any and all assumptions that were made.
4) Make sure your work is neat and legible.