Needed for database analysis and design I’m the owner of a small movie rental st

Question

Needed for database analysis and design

I’m the owner of a small movie rental store. We have over 3,000 movies that we need to keep track of. Each of our movies has a DVD or VHS 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 DVD or VHS contains the movie. A movie can be either DVD or VHS format. We always have at least one DVD or VHS tape for each movie we track, and each DVD or VHS tape is always a copy of a single, specific movie. Our DVDs and VHS tapes are very long. We don’t have any movies that require multiple DVDs or VHS tapes.

Write a list of nouns used in the scenario.

Name each entity.

Is each instance of the entity uniquely identifiable? Which attribute or attributes could serve as the unique attribute to identify the entity?

Explanation / Answer

Ok. First of all, let me list the nouns:

1. Movie rental store
2. movie
3. title
4. category
5. tape

Entities can be:
1. movie
2. tape (DVD or VHS)

The attributes which these two entities can have are:
1. movie can have the attributes
   a) movie ID -- to uniquely identify the movie
   b) title -- title of the movie
    c) category -- category of the movie
   d) no of copies -- how many copies of it are there

2. tape can have the attributes
   a) tape number -- to uniquely identify
   b) format (DVD or VHS) -- format of the movie it has
   c) movie ID -- to know which movie it has, by linking it with the movie entity.

So, if you are trying to make a RDBMS, you will have one table for MOVIE, and another for TAPE.

Primary key for MOVIE will be movie ID, and that for TAPE will be tape number.

movie ID will work as a reference key for TAPE.

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