R is a relation scheme R={A,B,C,D}.
(R是关系方案R = {A,B,C,D}。)
I have the functional dependencies below: B-->C, AC--> D, ABD--> C, BCD-->A is this relation in BCNF?(我具有以下功能依赖性:B-> C,AC-> D,ABD-> C,BCD-> A BCNF中的这种关系吗?)
can someone explain?(有人可以解释吗?)
thanks!(谢谢!)
ask by user12463947 translate from so