The database has been initialized, so now we get down to business of defining the fields in that database and include a field that we would call a foreign key which allows the establishment of the one to many relationship between the tables. This part of the process requires quite a bit of background of database creation, manipulation and handling. It also requires knowledge regarding the workings of data types. So assuming you do not have much knowledge in such areas do some more reading to give you a better understanding of what how and why they are there. The ROR developers might say that it is very easy to do and use ROR but without the background on logic formulation, data types and manipulation as well as database handling the rest of the posts which would tackle ever hardening topics and operations would be very difficult to make sense of.
Don’t get me wrong, we just want to make life easier for you and not have you not understanding anything at all.