Question

Consider the following relations for a database that keeps track of student enrollment in courses and books adopted for each course.

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STUDENT(Ssn,Name,Major,Bdate)

COURSE(Course#,Cname,Dept)

ENROLL(Ssn,Course#,Quarter,Grade)

TEXTBOOK(Book_isbn,Book_title,Publisher,Author)

BOOK_ASSOC(Course#,Quarter,Book_isbn)

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Having that a relation can have zero or more foreign keys and each foreign key can refer to different referenced relations. Specify the foreign keys for this schema.

Answer 1

Given that:

A foreign key is a column or composite of columns which is/are a primary key of other table that is used to maintain relationship between two tables.

• A foreign key is mainly used for establishing relationship between two tables.
• A table con have more than one foreign key.

The foreign keys in the given relations are as follows:

• Ssn is a foreign key in ENROLL table which references the Ssn of STUDENT table. Ssn is a primary key in STUDENT table.
• Course# is a foreign key in ENROLL table which references the Course# of COURSE table. Course # is a primary key in COURSE table.
• Course# is a foreign key in BOOK_ADOPTION table which references the Course# of COURSE table. Course# is a primary key in COURSE table.
• Book_ isbn is a foreign key in BOOK_ADOPTION table which references the Book_isbn of TEXT table . Book_isbn is a primary key in TEXT table.