(Choose 1 answer)
R(A,B,C,D)
S(B,C,D,E)
A. When B is the primary key of R
B. When B is the primary key or unique key of R
C. When B is the unique key of R
Suppose we have 2 relations:
When we say B is the foreign key of S?? (Choose the most correct answer)
Exit 14
