Check if record exists in Model Rails -

i wondering if need create custom validation following scenario.

i have prediction model, in user submits predicted scores set of football matches, grouped fixture_date.

if user has submitted predictions these games show error message stating unable submit error exists, or maybe not show form if predictions dates exist.at moment can create multiple sets of predictions same games. validation better. how go stating if prediction exists date current_user not submit?

so setup looks far

class prediction < activerecord::base   attr_accessible :home_team, :away_team, :home_score, :away_score, :fixture_date,   :fixture_id, :user_id  has_one :fixture end  class fixture < activerecord::base   attr_accessible :home_team, :away_team, :fixture_date, :kickoff_time, :prediction_id end 

predictions controller

 def index    @predictions = current_user.predictions if current_user.predictions  end   def new    @prediction = prediction.new  end   def create   begin   params[:predictions].each |prediction|     prediction.new(prediction).save!   end   redirect_to root_path, :notice => 'predictions submitted successfully' rescue   render 'new'  end end end 

im not sure relation between predictions , games. have game model? if should work:

class prediction < activerecord::base   attr_accessible :home_team, :away_team, :home_score, :away_score, :fixture_date, :fixture_id, :user_id    has_one :fixture    validates :fixture_id, :uniqueness => { :scope => :user_id, :message => "only 1 prediction per game allowed, each user" } end