PROTOTYPE DBMS
Week 2 Question 2
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Given the business rule “an employee may have many degrees,” discuss its effect on attributes, entities, and relationships. (Hint: Remember what a multivalued attribute is and how it might be implemented.)
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Sorayuth Chiewchansuwan
RE: Week 2 Question 2
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An employee may have many degree means that each employee may have more than one degree, Bachelor, Master, and PhD. Also, each degree can be earned by many employees. Therefore the relationship will be M:N relationship. However, the we can use the multivalued attribute to combine all the degrees in to one entity, for instance, we can name the entity as DEGREE and put PhD, Master, and Bachelor in it.
One problem we need to consider is that it will be very difficult to count them as all the information are gathered within the same entity.
Bert
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Ravi Karan Mallarapu
RE: Week 2 Question 2
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"An employee may have many degrees".
Here, employee ID alredy exists and is a field/attribute in itself. Hobbies requires a new field/attribute and comes under the entity of student details.
The relationship is 1:M and the model is based on how you build the table.
We can create a new table with fields for employee ID and every possible degrees. Here, the primary key of the employeeID becomes foriegn key in the new relation table. But, this model leads many null values which can be still operated.
If we use only a field for "hobbies" we need to assign the text field to contain more than one value. This is called as multivalued attribute. Here, a new schema is created with clear definitions of attributes about what type of attributes can be present and the number of instances of those values ie 1 or more. But still each value in a
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Given the business rule “an employee may have many degrees,” discuss its effect on attributes, entities, and relationships. (Hint: Remember what a multivalued attribute is and how it might be implemented.)
Reply Quote Email Author
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Set Flag 1 year ago
Sorayuth Chiewchansuwan
RE: Week 2 Question 2
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Top of Form
An employee may have many degree means that each employee may have more than one degree, Bachelor, Master, and PhD. Also, each degree can be earned by many employees. Therefore the relationship will be M:N relationship. However, the we can use the multivalued attribute to combine all the degrees in to one entity, for instance, we can name the entity as DEGREE and put PhD, Master, and Bachelor in it.
One problem we need to consider is that it will be very difficult to count them as all the information are gathered within the same entity.
Bert
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Message Unread
Mark as Unread
Message Not Flagged
Set Flag 1 year ago
Ravi Karan Mallarapu
RE: Week 2 Question 2
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Top of Form
"An employee may have many degrees".
Here, employee ID alredy exists and is a field/attribute in itself. Hobbies requires a new field/attribute and comes under the entity of student details.
The relationship is 1:M and the model is based on how you build the table.
We can create a new table with fields for employee ID and every possible degrees. Here, the primary key of the employeeID becomes foriegn key in the new relation table. But, this model leads many null values which can be still operated.
If we use only a field for "hobbies" we need to assign the text field to contain more than one value. This is called as multivalued attribute. Here, a new schema is created with clear definitions of attributes about what type of attributes can be present and the number of instances of those values ie 1 or more. But still each value in a