Ruby Rails BigDecimal 没有正确添加

Question

我正在尝试制作一个表格，用户可以在其中输入一个数字 (withdraw/deposit)，然后金额将显示在 post 中。但是，无论我尝试什么，BigDecimals 都不会加起来。

class MicropostsController < ApplicationController
  before_action :logged_in_user, only: [:create, :destroy]

  def create
    @micropost = current_user.microposts.build(micropost_params)
    if @micropost.save
      flash[:success] = "Micropost created!"
      current_user.update_attributes(deposit: deposits(@micropost.deposit), 
                                     withdraw: withdrawals(@micropost.withdraw),
                                     total: totals(@micropost.deposit, @micropost.withdraw)) 
      redirect_to root_url
    else
      @feed_items = []
      render 'static_pages/home'
    end
  end

  def deposits(money)
    return current_user.deposit + BigDecimal(money)
  end

  def withdrawals(money)
    return current_user.withdraw + BigDecimal(money)
  end

  def totals(dep, wit)
    return current_user.total + BigDecimal(dep) - BigDecimal(wit)
  end

  private

    def micropost_params
    params.require(:micropost).permit(:content, :deposit, :withdraw)
  end
end

所以当@micropost.deposit = 2.3 和@micropost.withdraw = 2.4 时，Rails 上的 Ruby 似乎都四舍五入到最接近的整数，输出为 4.0.

这也是我的表格

<%= form_for(@micropost) do |f| %>
  <%= render 'shared/error_messages', object: f.object %>
  <div class="field">
    <%= f.text_area :content, placeholder: "Compose new micropost..." %>
  </div>
  <div class="field">
    <%= f.text_field :deposit, placeholder: "Deposit. Input only positive numbers, e.g. 0.00" %>
  </div>
  <div class="field">
    <%= f.text_field :withdraw, placeholder: "Withdraw: Input only positive numbers, e.g. 0.00" %>
  </div>
  <%= f.submit "Post", class: "btn btn-primary" %>
<% end %>

Answer 1

我认为你有两部分问题：

BigDecimal - 如果您不希望它四舍五入为整数，则需要精度，因此 BigDecimal(1.7,1) 是 2 而 BigDecimal(1.7,2) 是 1.7
取款和存款字段的数据类型可能是 integer 而不是 decimal

Ruby Rails BigDecimal 没有正确添加

Ruby on Rails BigDecimal not adding properly

ruby-on-rails

bigdecimal