Most efficient way to login when multiple tables exist

[trollster]

Hello everyone, sorry for the dull title. Couldn't think of anything better. So this is my problem.I was using a registration form for teachers and one for students. There are ten fields in each, first name, last name, username, password, etc being similar whereas departments (teachers have 7, students have 3) and email ids (teachers have a different domain extension and students different) being different. I am using two tables, one for teachers and one for student.Now, I know I can use one login form, query against these two tables using the JOIN property and make them login. But I want to know if this method is efficient because two tables are being used.Or is this method more efficient: In the reg form, I put a radio button to select teacher or student and depending on what one chooses the remaining fields change, i.e, if I choose teacher, 7 departments show up or if I choose student only 3 of them show up. In this way, I have to use one table only, atleast I guess so.Or another possibility is I use two tables but two login forms, one for teacher and one for student, I know this is the easy way out but being a Comp Sci student I want to choose the efficient method of all.P.S: The teacher's role is going to be completely different from the student's in the site. And there will be lot of activities for the teachers and students, they are completely different. Will maintaining one table be a good bet?Thank you.

[justsomeguy]

It's sort of hard to answer that without more details. If they are sufficiently different then it makes sense to store them in different tables. If they are superficially different then it makes sense to store them in the same table with additional fields to identify the type of user. It's really your call to make, you know the details of the project.

[davej]

You lost me. The login has ten fields? What is the disadvantage of the radio button?