Question

Create ER Models & Normalization for the following scenarios:

1. A college needs to track placement test scores for all incoming students. Each student can take a variety of tests, including English and math. Some students are required to take placement tests because of previous coursework.

2. A movie megaplex needs to collect and analyze movie attendance data. The company maintains 16 theaters in a single location. Each movie offered can be shown in one or more of the available theaters and is typically scheduled for three to six showings in a day. The movies are rotated through the theaters to ensure that each is shown in one of the stadium-seating theaters at least once.

Answer 1

Hi Rhemalake812! The question is asking for Entity Relationship Diagrams and Normalization for 2 systems, one for a College subject enrollment system and the other for a Movies scheduling system. Please find the diagrams attached and the explanation below.

Step-by-step explanation:

An ERD shows the relationship between the Entities in the system. The first step is to identify the entities within the problem statement. For the college system, the Entities are College, Students, Subjects, Tests, and Coursework. When we draw the ERD based on the problem statement using these entities, we may come across relationships where data may be duplicated in the database tables (if there are many-to-many relationships). Therefore we normalize the data to remove the many-to-many relationships and have a design of one-to-many relationships or one-to-one relationships between the entities. It also helps to write out the relationships between entities in plain English, for example: "A college has many students enrolled in many subjects. Each subject has coursework that has many coursework items, and coursework items can have many tests."

The Entities in the Movie Megaplex system are Movie Megaplex, Location, Theatre, Schedule, Attendee, and Movies. For the Movies scheduling system, we can write in plain English like: "A movie megaplex can exist in many location, and a location has many theatres. A theatre has a schedule for showing many movies, and a movie can be shown in many theatres at a scheduled time to many attendees". Refer to the attachment ERDs to understand the relations with these statements as reference.