I am am developing a recruitment application for storing records of people who come for an interview. So I have two models - Applicant & Employee which seem like one in OO sense. i.e. Employee was earlier an applicant. Therefore I am planning to create a Single table inheritance like:
Applicant < Person
Employee < Person
All the fields of Applicant are there in Employee. Employee has several other fields that are not in Applicant.
Am I correct with this plan. I have another similar scenario to deal with - prospects & clients.
Update: As I am working more and more with STI, I am starting to dislike it.
As per my personal opinion , in OO point of view you are correct.
Applicant < Person
Employee < Person
But when it comes to database/ tables i will go for a one table called 'persons' (Person) that has all the columns for both 'Applicant' and 'Employee' and have a column with a flag indicating whether the Person is an Applicant or Employee
NOTE :: but this is only true if you have ONLY 'several other fields' not many
HTH
sameera
来源：https://stackoverflow.com/questions/5701178/rails-single-table-inheritance-or-not-for-applicant-employee-relationship