虽然觉得楼主好二，但是还是把答案给你吧，英文的哦Exercise 19.24 Prove that, if R has only one key, it is in BCNF if and only if it is in3NF.Answer 19.24 Let F (F+) denote the (closure of the) set of functional dependenciessatisfied by the schema R which is assumed to be in 3NF. We need to show that foreach nontrivial dependency X → A in F+, X is...
