详细

让用户指定要添加到现有列的数字如果用户指定3，并且现有列为97，则总共100和数字，100将被保存。

查看Set<String> updatedFields = new HashSet<>(updates.keySet());

split_now.html.erb

这是验证器

<div class="container">
 <h1>Split</h1>
 <%= form_for @currency, url: { action: 'split', controller: 'currencies'}, method: :put do |f|%>
  <% if @currency.errors.any? %>
      <div id="error_explanation" class="alert alert-danger">
        <h2><%= @currency.errors.count %>error(s) exist(s).</h2>
        <ul>
          <% @currency.errors.full_messages.each do |msg| %>
              <li><%= msg %></li>
          <% end %>
        </ul>
      </div>
  <% end %>
  <p>amount whatever you want to issue like 100</p>
  <div class="input-group">
    <%= f.text_field :amount,:class=>'form-control form-group',placeholder:"amount"%>
  </div>
  <%= f.submit 'done', class: "btn btn-large bg-info" %>
 <% end %>
</div>   


def split_now
  @currency=Currency.find_by_slug(params[:id])
end


def split
   @currency=Currency.find_by_slug(params[:id])
  if CurrencyUser.where(currency_id:@currency.id,owner:true).first.user==current_user
   if SplitValidation.new(amount:params[:amount]).valid?
    issue_more(params,@currency)
    else
    render "split_now"
    end
  else
    redirect_to @currency,alert:"This currency wasn't issued by you"
  end
end

def issue_more(params,currency)
   result=false
   current_amount=currency.amount
  result=currency.update(
            amount:current_amount+params[:amount].to_i
  )
 currency_user=CurrencyUser.find_by(currency_id:currency.id,owner:true)
 currency_user.update(amount:currency_user.amount+params[:amount].to_i)
 return result
end`

路由

class SplitValidation

 include ActiveModel::Model
 attr_accessor :amount
 validates :amount, presence: true,numericality: { only_integer:  true,greater_than: 0 }

end

Answer 1

尝试以下内容，我想你想要这样：

currency_user.increment('amount', params[:amount].to_i)

或

currency_user.increment!('amount', params[:amount].to_i)

或

currency_user.update_attributes({'amount': currency_user.amount + params[:amount].to_i})

或

currency_user.update_attribute(amount: currency_user.amount + params[:amount].to_i)

<强>更新

以下方法跳过验证，并将对象保存到数据库，无论其有效性如何。应谨慎使用它们。 Skipping Validations

更新2

要进行验证，您可以使用HTML默认验证器<input type="number" min="1" name="number" step="1" required/>，请参阅以下代码并附上alert示例，只需按下即可运行，看看发生了什么。

$(document).on('submit', '#myForm', function(e){
    e.preventDefault();
    var formData = $(this).serialize();
    alert(formData);
});

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<form id="myForm" action="//google.com">
  <p>Input type number step any</p>  
  <input type="number" min="1" name="number" step="1" required/>
    <input type="submit"/>
</form>

希望它能奏效。

如何从更新以外的操作更新现有列？

详细

1 个答案: