What's the Foreign Key(s) of the students table?

2) What's the Foreign Key(s) of the Classes table?

3) What's the Foreign Key(s) of the Courses table?

 

4) What's the Foreign Key(s) of the Enrollments table?

 

 

Students Snum Sname Courses Major 101 Andy IS 102 Betty IS 103 Cindy FIN 104 David FIN 12232 GPA Dept Code Title CrHr 2.5 2.8 3.1 2.4 5885 IS 300 Intro to MIS IS 301 Statistics MKT 301 Intro to Marketing 3 MKT 304 Int'l Marketing mmmm 3 3 105 Ellen MKT 3.8 106 Frank IS 3.8 Classes Enrollments CallNum Dept Code Section# Semester SNUM CallNum GRADE 10111 IS 300 1 2004Fa 101 10111 10112 IS 300 2 2004Fa 102 10111 10113 IS 301 1 2004Fa 103 10111 10114 IS 300 1 2005Sp 101 10114 10115 IS 300 2 2005Sp 102 10116 10116 MKT 301 1 2005Sp 103 10116 10117 MKT 301 2 2005Sp 103 10114 102 10114 ABABAACA