On 23 February 2010 19:40, ben wiseley <wisel...@gmail.com> wrote: > you need > has_and_belongs_to_many http://railsbrain.com/api/rails-2.3.2/doc/index.html?a=M001888&name=has_and_belongs_to_many
How, precisely will a join-table help, when he says that "Normalizing the DB is out of the question"? :-/ On 23 February 2010 19:32, pepe <p...@betterrpg.com> wrote: > Hi, > > Working with legacy DB here... > > 2 tables: > Projects > Workers > > A worker record has many fields in it to hold project codes as in: > project1, project2, project3, ... project30 (great, isn't it?...) > > Normalizing the DB is out of the question. > > I've been thinking about this for a while and I can't find a way to > associate both tables as in: > > "Project has_many :workers" > "Worker.project1 belongs_to :project" > "Worker.project2 belongs_to :project" > etc. > You are highly limited given your inability to re-structure the database, and I wonder whether you want to reconsider negotiation with whatever powers that be to refactor the database a little (or a lot! ;-) But working with the tables you have, you can at least use AR as much as possible... # worker model belongs_to :project1, :class_name => "Project", :foreign_key => "project1_foreign_key_name_in_workers_table" belongs_to :project2, :class_name => "Project", :foreign_key => "project2_foreign_key_name_in_workers_table" belongs_to :project3, :class_name => "Project", :foreign_key => "project3_foreign_key_name_in_workers_table" The project model is going to be harder, and you're not going to be able to intuitively assign workers to projects, but you can at least fudge-together some helper methods to make it look like you're leveraging the power of Rails! :-) #project model has_many :project1_keyed_workers, :class_name => "Worker", :foreign_key => "project1_foreign_key_name_in_workers_table" has_many :project2_keyed_workers, :class_name => "Worker", :foreign_key => "project2_foreign_key_name_in_workers_table" has_many :project3_keyed_workers, :class_name => "Worker", :foreign_key => "project3_foreign_key_name_in_workers_table" def workers # build and array of all the arrays of workers, flatten it and get rid of nil values ([] << project1_keyed_workers << project2_keyed_workers << project3_keyed_workers).flatten.compact end Hope this helps.... Michael -- 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-t...@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.
