从控制器Ruby On Rails插入数据到数据库？

Question

在我的def在casting_controller中创建函数。我创建一个Casting对象并保存它。这是好的，但我也想创建一个LinkCastingToModel对象，从我的控制器向它插入数据，但是当我检查时，数据始终为零。我如何插入数据到它

def create 
    @casting = Casting.new(casting_params) 
    @casting.models_booked = 0 
    link = LinkModelAndCasting.new 
    link.client_id = @casting.id 
    link.save 
    # link_model_and_casting = LinkModelAndCasting.new(:casting_id => @casting.id) 
    # link_model_and_casting.save 

    respond_to do |format| 
    if @casting.save 
     format.html { redirect_to @casting, notice: 'Casting was successfully created.' } 
     format.json { render :show, status: :created, location: @casting } 
    else 
     format.html { render :new } 
     format.json { render json: @casting.errors, status: :unprocessable_entity } 
    end 
    end 
end 

我使用postgresql，谢谢。

Answer 1

这是因为，当你从@casting.id分配clinet_id到link，到那时@casting没有保存，所以id实际上是nil。

您必须在此之前致电@casting.save。然后它会工作。就像这样：

def create 
    @casting = Casting.new(casting_params) 
    @casting.models_booked = 0 
    @casting.save 
    link = LinkModelAndCasting.new 
    link.client_id = @casting.id 
    link.save 
    # link_model_and_casting = LinkModelAndCasting.new(:casting_id => @casting.id) 
    # link_model_and_casting.save 

    respond_to do |format| 
    if @casting.id 
     format.html { redirect_to @casting, notice: 'Casting was successfully created.' } 
     format.json { render :show, status: :created, location: @casting } 
    else 
     format.html { render :new } 
     format.json { render json: @casting.errors, status: :unprocessable_entity } 
    end 
    end 
end