Lab Questions
ieas2010
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Lab 1 : 40 Total Points Possible
Section 3: Identifying Relationships ( 2 2 Points)
Section 4: Supert ypes and Subtypes ( 18 Points)
Section 3 Objectives :
• Interpret and describe relationship optionality
• Interpret and describe relationship cardinality
• Relate entities by applying the rules of cardinality and optionality
Vocabulary :
Directions: Identify the vocabulary word for each definition below.
1. A property of an end of a relationship between X and Y, that describes how many of X is related to Y. (2 Points)
Answer:
2. A connection or association between objects. (2 Points)
Answer:
3. A property of an end of a relationship between X and Y, that describes whether X must be or may be related to Y. (2 Points)
Answer:
Try It / Solve It :
When naming the relationships below, you will need to follow the components of
ERDish:
- EACH
- Entity A
- OPTIONALITY (must be/may be)
- RELATIONSHIP NAME
- CARDINALITY (one and only one/ one or more)
- Entity B
The example below is what your answers should include with two ERDish sentences and a diagram of the relationship between the entities.
My Example:
1. Each MANAGER may manage one or more EMPLOYEE
2. Each EMPLOYEE must be manage d by one and only one MANAGER
Example of ERD for relationship above:
manage
MANAGER
EMPLOYEE
managed by
Your Turn:
1. Read the given business scenario below. Name the relationships using ERDish sentences between EMPLOYEE and JOB. Draw soft boxes with the entity name and identify appropriate optionality and cardinality.
“We have a lot of employees who handle one or more different jobs. We’d like to keep track of who is working on which job. Although employees can help each other, a job is assigned to one employee and is the ultimate responsibility of that individual. All our employees have at least one job. However, there are jobs that are not yet assigned to anyone.”
ERDish Sentences (2 points) :
1.
2.
ERD (2 points):
2. Read the given business scenario below. Name the relationships using ERDish sentences between ORDER and WAITER. Draw soft boxes with the entity name and identify appropriate optionality and cardinality.
“We assign our waiters to certain areas, except for our trainees, who just observe and are not responsible for taking any orders yet. A waiter takes the orders for the tables in his/her area. All areas have one assigned waiter. A customer places an order with a waiter. If the customer has a question or wants to make a change to the order, he/she needs to request this with the assigned waiter.”
ERDish Sentences (2 points) :
1.
2.
ERD (2 points):
3. Read the given business scenario below. Name the relationships using ERDish sentences between PARENT and CHILD. Draw soft boxes with the entity name and identify appropriate optionality and cardinality.
“At the end of each day, parents need to pick up their children at our day-care center. All children must be picked up by 6 p.m. A child may have two parents, but we need only one of them to come and pick up their child or their children. We cannot release a child to anyone but that child’s parents.”
ERDish Sentences (2 points) :
1.
2.
ERD (2 points):
4. Read the given business scenario below. Name the relationships using ERDish sentences between TEACHER and STUDENT. Draw soft boxes with the entity name and identify appropriate optionality and cardinality.
“Some students request remedial help in certain subjects, such as math. We can assign a tutor who can work with the student after class. Some of our teachers agree to be tutors. If several students need tutoring in one subject, then we assign them to the same teacher. If a student needs tutoring in several subjects, then he/she will probably be assigned to several different tutors.”
ERDish Sentences (2 points) :
1.
2.
ERD (2 points):
Section 4 Objectives :
• Define and give examples of a subtype and supertype
• State the rules relating to entities and subtypes
• Apply the rules of supertype and subtype by evaluating the accuracy of ER diagrams that represent them
Vocabulary :
Directions: Identify the vocabulary word for each definition below.
1. All subtypes are listed without omission. (2 Points)
Answer:
2. A means of classifying an entity that has subtypes. (2 Points)
Answer:
3. Something an entity may be split into based on common attributes and/or relationships. (2 Points)
Answer:
4. Each instance of a supertype is an instance of only one possible subtype. (2 Points)
Answer:
Try It / Solve It :
1. Determine which of the following is the supertype, then identify the remaining subtypes. ( 5 Points)
Amputation =
Visual Impairment =
Hearing Impairment =
Disability =
Paralysis =
2. Draw a diagram below illustrating the supertype/subtypes identified above. (5 Points)
