# For the given business rule,  is the explanation for relationship and cardinality correct between PROFESSOR and COURSE below:   Business Rule:  A university is divided into many schools. Each school has many departments, where each department belongs to one and only one school.  Each department should have one or more professors assigned to it, where each professor cannot teach more than two courses.  The university wants to record the following data for all professors: professor number and full name.  All courses are classified into two categories: Fashion and Technology.       Relationship:  PROFESSOR “teaches” COURSE   Relationship type:  1:M Explanation:  Business rules state, “Each course belongs to one and only one professor.  Each professor includes one or more courses”.  The PROFESSOR entity is on the “one” side of the relationship and the COURSE entity is on the “one or more” side of the relationship.   Relationship participation: Mandatory on the “one” side of the relationship and mandatory on the “one or more” side of the relationship. Explanation:  The PROFESSOR entity is mandatory in the relationship because” Each course belongs to one and only one professor”.  The COURSE entity is mandatory in the relationship because “Each professor teaches one or more courses”, so a professor must teach at least one or more courses.    Cardinality: The cardinality of PROFESSOR is (1,1) The cardinality of COURSE is (1, N)

Question

For the given business rule,  is the explanation for relationship and cardinality correct between PROFESSOR and COURSE below:

A university is divided into many schools. Each school has many departments, where each department belongs to one and only one school.  Each department should have one or more professors assigned to it, where each professor cannot teach more than two courses.  The university wants to record the following data for all professors: professor number and full name.  All courses are classified into two categories: Fashion and Technology.

Relationship:  PROFESSOR “teaches” COURSE

Relationship type:  1:M

Explanation:  Business rules state, “Each course belongs to one and only one professor.  Each professor includes one or more courses”.  The PROFESSOR entity is on the “one” side of the relationship and the COURSE entity is on the “one or more” side of the relationship.

Relationship participation: Mandatory on the “one” side of the relationship and mandatory on the “one or more” side of the relationship.

Explanation:  The PROFESSOR entity is mandatory in the relationship because” Each course belongs to one and only one professor”.  The COURSE entity is mandatory in the relationship because “Each professor teaches one or more courses”, so a professor must teach at least one or more courses.

Cardinality:

• The cardinality of PROFESSOR is (1,1)
• The cardinality of COURSE is (1, N)