OCL1 - Fall, 2004 - Johnson
Lab 1
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a. Using two entity sets, model people living in residences, on the assumption that everybody lives in exactly one house.
b. Using two entity sets, model people living in rent-controled NYC apartments, on the assumption that no one may rent a rent-controlled
apartment unless it's his primary residence. Of course, many people don't get rent-controlled apartments...
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Draw an E/R diagram to capture the following situation.
Entity sets:
- Empoyees
- Projects
- Departments
Relationships:
- assigned-to(employees, departments)
- works-on(employees, projects)
- boss-of(employees, employees)
- manages(employees, departments)
Assume that each person has exactly one boss but may work on multiple projects; multiple employees may work on the same project.
- An individual webpage has:
- a domain name (the usual .com addresses)
- a IP addresses (also picking out the domain)
- a filename and path
- links to other pages
Create an E/R diagram representing this situation.
- Think of a situation to model in which there are at least three kinds of entities and at least two entities
of different multiplicities. Clearly describe the situation and give an E/R model.
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