Nic*_*5a1 8 ruby-on-rails has-and-belongs-to-many ruby-on-rails-3 ruby-on-rails-3.1
我有2个模型(Workout,Equipment)中有一个属于很多关系.如果我使用Workout.find(:all, :joins => :equipment, :conditions => "equipment.id = 5")它,但如果我使用Workout.find(:all, :joins => :equipment, :conditions => "equipment.id = null")它不会返回没有关联的记录.有任何想法吗？
Jam*_*msi 10
给它一个旋转;
Workout.joins("left join equipments e on workouts.id = e.workouts_id").where("e.id is null")