E-R图与实际的数据库究竟是什么关系，外键什么的如何在er图中表现？

可以设计3个表 1 staff(fullname,no,uk address ,email, chinesemobile number,gender,staff number,visa expdate,flight number,book cinfirmation) 2 flight(flight number,arrival time,take off time, remaks,limo number) 3 hotel(arrival date,depature date,romm number,