Question

Database

Could you help me to solve the problem? Thank you very much!

In most colleges and universities such as SJSU, which of the following functional dependence is valid 14 | (a) Student-ID → Grade (b) Instructor-ID → Class-Code (c) Instructor-Last-Name → Instructor-ID (d) none of the above A well-designed relational database table usually has many multi-valued columns: 15 (a) true (b) false 16 Can a foreign key column contain duplicate values? (a) yes (b) no

Answer 1

--14

Student-Id->Grade is valid functional dependency. Because Grade of students can be identified unique by Student-Id. Id is unique for each student.

Instructor -Id -> Class - Code is not functional dependencies because both are unique and can be identified without any on of entity.

Instructor-Lastname->Instructor-id is not functional dependencies because last name can be repetitive and cannt identify instrutoin id with help of LastName

--15

False (Multivalued parameters will be removed in 1NF. A well designed database will be in 3NF or 2NF)

--16

Yes (Foreign key is repetitive. It is primary key of some other table. For example- Class -id is unique key of class table. In students table it will be repetitive because same class can be tagged to multiple students)

Please comment if any clarification required