On Aug 7, 12:43 am, MC <amev...@gmail.com> wrote: > Frederick, > > I would want to be able to see what students are being taught be what > instructor. And yes I would want to be able to know what the course > the student is taking. So from my current setup are you saying I > wouldn't get that? Or would I get that if I used a :through > association?
It depends on the reality you are modelling. At the moment, a student belongs_to instructor, which has_many courses - how can you extract from that which course a student on. Is it really the case that a student always has the same instructor, no matter what combination of courses? > I'm sort of having a tough time wrapping my head around the > associations. I read the rails guide on associations but it's not > sticking yet. Is the whole point of associations being able to make > calls to the records because of active record's built in > capabilities? > Using associations does get you all that, but before thinking about that I think you need to step back and think about the data you are trying to model and what questions you will need to be able to answer. For example with you current setup, you can't represent a student having one instructor for their Spanish course and a different one for their Russian literature (but only you can say whether or not this restriction is ok). To me if feels like you want a join model between courses and students that defines which courses a student is taking and with which instructor, but I don't know precisely what the reality that you are trying to model > With regard to what you mentioned about CourseDate and CourseTime and > just making them additional columns. Could I still call that > information and post it to a calendar some how? > > My confusion over relationships starts making me think that I should > make everything an object class. Has anyone else felt this way? Is > there a guideline for when you make something it's own class as > opposed to just making it a column in a table? > You haven't said what is in those tables. If they just a simple date and a simple time column, then i don't think there's any reason. If you're managing a more complicated schedule then it might deserve its own table (e.g. if course date meant something like 'tuesdays and thursdays'). Bottom line is I would ask myself for the given situation - what data might I be duplicating - how does this change my ability to ask (efficiently) the questions that I want to answer (e.g. 'what courses are on today' or 'when does this course start) If there's no benefit to having a separate table then that suggests to me that the things in question are more naturally just attributes. Fred. > Mark > > On Aug 6, 2:42 am, Frederick Cheung <frederick.che...@gmail.com> > wrote: > > > > > > > > > On Aug 6, 9:07 am, MC <amev...@gmail.com> wrote: > > > > First crack at an app. I have a friend with a private school that I'm > > > trying to create a scheduling system for. > > > > So I have Coordinators creating school courses. Once the course is > > > created the coordinator can assign multiple instructors, and then > > > assign students to the course and instructor. So is this right? > > > Are you even going to need to have students that belong to multiple > > instructors? Are you going to want to know what course the student is > > taking ? From the associations you've given you don't seem to be > > storing that bit of information, the best you could work out is that > > given their instructor there are only certain courses they could be > > doing. > > > > Then the other thing I want to do is set a date and time for each > > > course. So would I create this also: > > > > class CourseDate > > > belongs_to :course > > > end > > > > class CourseTime > > > belongs_to :coursedate > > > end > > > Without a full understanding of your problem (perhaps you are managing > > repeating occurrences of courses etc.) this feels a little overkill to > > be honest. would date/time columns on your courses table not suffice? > > > Fred > > > > Thanks in advance, Mark -- You received this message because you are subscribed to the Google Groups "Ruby on Rails: Talk" group. To post to this group, send email to rubyonrails-talk@googlegroups.com. To unsubscribe from this group, send email to rubyonrails-talk+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/rubyonrails-talk?hl=en.
