問題詳情
14. According to the three database tables listed below, which of the following statements is CORRECT if you want to create a relational database model?
(A) There is no possible foreign key that can be used in“Purchase”table.
(B) EID can be regarded as a primary key in“Purchase”table.
(C) There is a one-to-many relationship between“Employee”and“Purchase”tables.
(D) Every table must have a foreign key to uniquely identify a particular row.
(E) If we want to query Employee’s names in the Purchase with PID= "1234" and "1238", it is a better approach to use UNION in SQL command.
參考答案
答案：C
統計：A:0,B:0,C:0,D:0,E:0
難度：計算中