Rails - Feb 2006 - complicated search/model question

Hi,

I have the models and db below and am putting together a scheduling application.
With what is laid out below (or any suggested changes) how would I find a
contractor for a job based on the contractor being available on a specific
weekday, at a specific time and not currently booked in to a job during the
same time?

I?m new to Ruby and Rails and making pretty good progress but I must admit I
have no idea were to start on this.

Thanks in advance for any help,

Hugh

contractor.rb
has_many :jobs
has_many :availabilities

job.rb
belongs_to :contractor

availability.rb
belongs_to :contactor


create_table "availabilities", :force => true do |t|
    t.column "contractor_id", :integer
    t.column "day", :integer # 0-6 to match  ruby wday
    t.column "available_from", :datetime # could be just a time field
but rails
doesn''t seam to play nice with time objects
    t.column "available_to", :datetime # could be just a time field
but rails
doesn''t seam to play nice with time objects
    t.column "start_date", :date # used if a contractor available only
between
certain dates
    t.column "end_date", :date # used if a contractor available only
between
certain dates
    t.column "comments", :string
    t.column "created_at", :datetime
    t.column "update_at", :datetime
  end

  create_table "jobs", :force => true do |t|
    t.column "created_at", :datetime
    t.column "updated_at", :datetime
    t.column "contractor_id", :integer
    t.column "date_time", :datetime
    t.column "duration", :float
    t.column "booking_id", :integer
    t.column "confirmed", :datetime
    t.column "cancelled", :datetime
  end

  create_table "contractors", :force => true do |t|
    t.column "created_at", :datetime
    t.column "updated_at", :datetime
    t.column "first_name", :string
    # plus a bunch more
  end

end

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