I was able to create a has_and_belongs_to_many relationship for my app, but now I'm not too sure how to write queries for it. Basically, I have a table 'courses' that has_and_belongs_to_many 'categories' and vice versa So I'm trying to figure out how I would find only the courses that belong to a category that I specify. Let's say the category is 'math' and the categories are in a column named 'name' Any help would be great.
on 2006-05-08 06:23
on 2006-05-08 06:28
Category.find(:first, :condition => "name = math").courses Or something to that effect should do the trick. On 5/7/06, Ben <email@example.com> wrote: > named 'name' > > Any help would be great. > > -- > Posted via http://www.ruby-forum.com/. > _______________________________________________ > Rails mailing list > firstname.lastname@example.org > http://lists.rubyonrails.org/mailman/listinfo/rails > -- Ben R. 303-947-0446 http://www.benr75.com
on 2006-05-08 06:32
@courses_in_cat = Category.find_by_name('math', :first).courses This should give you back an array for all the courses in the math category. The opposite is also true. @categories_for_course = Course.find_by_name('some course', :first).categories To add Courses to a Category @some_category << @an_array_of_courses and vise versa @some_course << @an_array_of_categories