im building a database on virtual private server hosting, i have used the following entities, its my project for the college, i want to be sure if im doing it all correct, i have to make its ERD on visio enterprise architect, can any one suggest me more entities for VPS ? are my relations correct? customerDetail (pid, fname, lname, sid, postalcode, country, telno) Ccode (postalcode, city) Edetail (empid, empname, empadd, emptel, empposition) Edesig (empposition, empsalary ) Sales (sno, pid, sid, durationfor, cardno, empid) invoiceline( INid, sid, sno, empid, bill ) Transaction (cardno, cardtype, expiry, cvv) Orders (pid, sno status) VPSDetail (sid, sname, size, ram, os, bandwidth, price)