Question

1- [4 Marks] Create an ER diagram for a movie theater company. The company had its registered number and name of the company. The company may own many theaters, and each theater has unique Id, name, and address. Every theater must be owned by one or more companies. In each theater, multiple movies can be played. However, each movie may be played in one theater only. A movie can be played on one or multiple screens; every screen has id and seating capacity and each screen must display exactly one movie

Answer 1

Explanation: Here Company entity set has two attributes which are Registered Number and Company name here Registered Number is Primary key denoated by underline text.

Theater entity has three attributes they are Id, Name and Address here Id is primary key, and Address is compound key which contain three more attributes such as pincode, state and country.

Company and Theater entity Related to each other such that each company may own more than one Theater and each Theater needs to be owned by at least one company double arrow represents total participation of Theater entity set which ensures that each theater is owned by at least one or more company.

Screen Entity has two attributes they are id and capacity here id is primary key and capacity is a single attribute.

Theater and Screen entity has one to many relationship which means one Theater may have more than one Screen.

Movie and Screen screen Entity is related via many to one relationship which means one Movie can be played on a single or multiple screens.