update_attributes中where子句的Rails错误

Question

我有一个没有主键的表，有三列-- Player_ID、Season和Amount。当我想要更新当前的表时，我会收到这样的错误消息: ActiveRecord::StatementInvalid (Mysql2:: error : Unknown column 'salaries.‘在'where子句‘中: UPDATE salaries SET Season = 20192，Amount = 3232.0 WHERE salaries.为NULL)

我的控制器中的更新方法：

def new
  @salary = Salary.new
  @players = Player.all
  @title = "Add salary"
end

def create
  @players = Player.all
  @salary = Salary.new(params[:salary])
  if @salary.save
    flash[:success] = "Successfully added salary"
    redirect_to salaries_path
  else
    @title = "Add salary"
    render 'new'
  end
end

def edit
  @player_id = params[:player_id]
  @season = params[:season]
  @salary = Salary.find_by_Player_ID_and_Season(params[:player_id], params[:season])
  @players = Player.all
  @title = "Edit salary"
end

def update
    @players = Player.all
    @player_id = params[:player_id]
    @season = params[:season]
    @salary = Salary.find_by_Player_ID_and_Season(params[:player_id], params[:season])
    if @salary.update_attributes(params[:salary])
       flash[:success] = "Successfully edited salary"
       redirect_to salaries_path
    else
       render 'edit'
    end
  end

_form.html.erb

<%= form_for(@salary, :url => salary_path(:player_id => @player_id, :season => @season)) do |f| %>
  <%= f.collection_select :Player_ID, @players, :ID, :Name %>
  <%= f.text_field :Season %>
  <%= f.text_field :Amount %>
  <%= f.submit "Add" %>
<% end %>

Answer 1

活动记录模型必须有一个主键，否则不能更新或删除行。

如果您确实不想向表中添加ID列，那么可以使用composite_primary_keys gem (尽管添加主键肯定是阻力最小的方法)

Answer 2

您的表已经有主键！这是id属性。params[:season] ...我想是params[:salary][:season]，对吧？我认为你应该用小写的season, player_id, amount写。之后，如果仍然有问题，请在此处发布新代码^^

Answer 3

我知道你出错的原因，尽管根本原因我不是很清楚。失败的查询是这样的：

ActiveRecord::StatementInvalid (Mysql2::Error: Unknown column 'salaries.' in 'where clause': UPDATE salaries SET Season = 20192, Amount = 3232.0 WHERE salaries.`` IS NULL)

重要的部分是：

WHERE salaries.`` IS NULL

如果它是WHERE salaries.foo IS NULL或WHERE salaries.bar IS NULL，这会有一定的意义，但您只需要在列名通常所在的位置留出空格。因此，我猜MySQL (出于某种奇怪的原因)将其解释为您正在讨论一个名为salaries (即salaries.salaries)的列，但该列并不存在。

我甚至不知道为什么WHERE子句会放在第一位。

您的create操作有效吗？

更新：问题几乎可以肯定是这一行：

if @salary.update_attributes(params[:salary])

我相信你想要的是：

if @salary.update_attributes(:amount => params[:amount])

看看有没有什么用。