Activity:  Homework

 

1. Examine the nouns. Are they things of significance?

 

2. Name each entity.

 

3. Is there information of interest about the entity that the business needs to hold?

 

4. Is each instance of the entity uniquely identifiable? Which attribute or attributes could serve as its UID?

 

5. Write a description of the entity.

 

6. Diagram each entity and a few of its attributes.  Remember, entity names are always singular.

 

7. Identify the relationships and draw them on the ERD.

 

 

Video Store

 

“I’m the owner of a small video store. We have over 3,000 video tapes that we need to keep track of.

 

Each of our video tapes has a tape number. For each movie, we need to know its title and category (e.g., comedy, suspense, drama, action, war, or sci-fi).

 

"Yes, we do have multiple copies of many of our movies.

 

"We give each movie a specific ID, and then track which movie a tape contains. A tape can be either DVD or VHS format.

 

"We always have at least one tape for each movie we track, and each tape is always a copy of a single, specific movie.

 

"Our tapes are very long. We don’t have any movies that require multiple tapes."

 

"We are frequently asked for movies starring specific actors. John Wayne and Julia Roberts are always popular. So we’d like to keep track of the star actors appearing in each movie. Not all of our movies have star actors. Customers like to know each actor’s “real” birth name and date of birth. We track only actors who appear in the movies in our inventory."

 

"We have lots of customers. We rent videos only to people who have joined our 'video club.' To belong to our club, they must have good credit. For each club member, we’d like to keep their first and last name,

current phone number, and current address. And, of course, each club member has a membership number.

 

Then we need to keep track of what video tapes each customer currently has checked out. A customer may check out multiple video tapes at any given time. We just track current rentals. We don’t keep track of any rental histories.”