DBI202Xuất hiện trong 1 đề thi
Given the relation schema $R(A,B,C,D)$ and functional dependencies $F = \{A \to C,\ D \to B\}$. Which functional dependency/ies can cause a violation of second normal form (2NF)?
Các lựa chọn
A$A \to C$
B$D \to B$
Cboth $A \to C$ and $D \to B$
DNeither $A \to C$ nor $D \to B$