Ruby 2＆Rails 4 Query在开发中返回结果，但在生产中返回nil

Question

We are writing an application in ruby on rails and we are experiencing an oddity. When we run the app in development our query returns just fine. When we run the app in production our query returns nil, even with records in the database. I have queried directly through MySQL Server so I know the records are there.

Any Ideas? I have included the error, migration, model, controller and view code.

The error I get is

undefined method `each' for nil:NilClass

Extracted source (around line #19):

          @count = 1
          if @leadsHot != nil || @leadsHot != ''
          @leadsHot.each do |lead| %>
          <tr role="row" <% if @count / @count == 0 %>class="gradeA even"<% else %> class="gradeA odd" <% end %>>
          <td class="sorting_1"><%= lead.category.to_s %></td>
          <td><%= lead.fname.to_s %> <%= lead.l_name.to_s %></td>

Migration File

  class CreateLeads < ActiveRecord::Migration
  def up
    create_table :leads do |t|
      t.column :category, :string
      t.column :patent_status, :string
      t.column :over_eighteen, :string
      t.column :salute, :string
      t.column :fname, :string
      t.column :m_initial, :string
      t.column :l_name, :string
      t.column :address, :string
      t.column :address1, :string
      t.column :city, :string
      t.column :state, :string
      t.column :zip,:string
      t.column :phone, :string
      t.column :cell_phone, :string
      t.column :fax, :string
      t.column :email, :string
      t.column :user_id, :integer
      t.column :source, :string
      t.column :lead_source_id, :integer
      t.column :hot, :boolean, :null => false, :default => 0
      t.column :comments, :text
      t.column :active, :boolean
      t.timestamps null: false
    end
  end

  def down
    drop_table :leads
  end
end

Model

class Lead < ActiveRecord::Base
    has_one :lead_source
    accepts_nested_attributes_for :lead_source

    has_many :lead_contact_logs
  end

Controller

class Backoffice::SalesController < ApplicationController
  include LogIt
  include LeadManagement
  include SalesModule
  include TableDataMethods
  def dashboard
    @leadsAll = Lead.all().where("hot=0 AND active=1") #getvalidleads
    @leadsHot = Lead.all().where("hot=1 AND active=1")  #getHotLeads
    @leadsDOA = Lead.all().where("active=0") #getRecentDeadLeads
    @curClients = basicCurrentClientsTable
    if @curClients == nil
      @curClients = "<tr><td colspan='7'>No Clients Available</td></tr>"
    end
    if @leadsHot == nil
      @leadsHot = "<tr><td colspan='7'>No Hot Leads Available</td></tr>"
    end
  end
end

View

<div class="panel-body" style="display: none;">

    <table aria-describedby="data-table_info" role="grid" class="table table-striped table-bordered nowrap dataTable no-footer dtr-inline" id="hotLeads">
      <thead>
      <tr role="row">
        <th aria-label="Lead Category: activate to sort column descending" aria-sort="ascending" colspan="1" rowspan="1" aria-controls="data-table" tabindex="0" class="sorting_asc">
          Lead Category
        </th>
        <th aria-label="Contact Name: activate to sort column ascending" style="" colspan="1" rowspan="1" aria-controls="data-table" tabindex="0" class="sorting">Contact Name</th>
        <th aria-label="Phone: activate to sort column ascending" style="" colspan="1" rowspan="1" aria-controls="data-table" tabindex="0" class="sorting">Phone</th>
        <th aria-label="Email: activate to sort column ascending" style="" colspan="1" rowspan="1" aria-controls="data-table" tabindex="0" class="sorting">Email
        </th>

        <th aria-label="ACTIONS: activate to sort column ascending" style="" colspan="1" rowspan="1" aria-controls="data-table" tabindex="0" class="sorting">
          ACTIONS
        </th>
      </tr>
      </thead>
    <tbody>
    <%
          @count = 1
       if @leadsHot != nil || @leadsHot != ''
       @leadsHot.each do |lead| %>
        <tr role="row" <% if @count / @count == 0 %>class="gradeA even"<% else %> class="gradeA odd" <% end %>>
          <td class="sorting_1"><%= lead.category.to_s %></td>
          <td><%= lead.fname.to_s %> <%= lead.l_name.to_s %></td>
          <td><%= lead.phone.to_s %></td>
          <td><%= lead.email.to_s %></td>
          <td>
            <div class="btn-group m-r-5 m-b-5">
              <a href="javascript:;" class="btn btn-success">Actions</a>
              <a href="javascript:;" data-toggle="dropdown" class="btn btn-success dropdown-toggle">
                <span class="caret"></span>
              </a>
              <ul class="dropdown-menu pull-right">
                <li><a href=/backoffice/sales/view_lead?id=<%= lead.id %>">View</a></li>
                <li><a href="/backoffice/sales/edit_lead?id=<%= lead.id %>">Edit</a></li>
                <li><a href="mailto:<%= lead.email %>">Email - <%= lead.email %></a></li>
                <li><a href="/backoffice/process/new_client/create_client?id=<%= lead.id %>">Convert To NEW CLIENT</a></li>
                <li><a href="/backoffice/sales/edit_lead?id=<%= lead.id %>&update=makeDead">Convert To DEAD LEAD</a></li>
              </ul>
            </div>
          </td>
        </tr>
    <% end %>
    <%
       else
    %><tr><td colspan="7"><h5>No Hot Leads in the system.</h5></td></tr><%
       end
    %>
    </tbody>
  </table>
</div>

rails console production results

   2.2.1 :004 > Lead.all().where(active: true, hot: true)
  Lead Load (0.8ms)  SELECT `leads`.* FROM `leads` WHERE `leads`.`active` = 1 AND `leads`.`hot` = 1
 => #<ActiveRecord::Relation [#<Lead id: 1, category: "Cars", patent_status: "none", over_eighteen: "Yes", salute: "Mr", fname: "Middleton", m_initial: "Jacksonmade", l_name: "Longtrowsers", address: "303 Springfield Ave", address1: "Apt D", city: "Lancaster", state: "North Carolina", zip: "97055", phone: "(803) 320-7672", cell_phone: "803-320-7672", fax: "", email: "george@betazedsoftwaresolutionsinc.com", user_id: nil, source: "Call In", lead_source_id: nil, hot: true, comments: "sdgsadfasdg", active: true, created_at: "2015-12-10 08:45:59", updated_at: "2015-12-10 08:45:59">, #<Lead id: 2, category: "Cars", patent_status: "Yes", over_eighteen: "Yes", salute: "Mr.", fname: "Furgo", m_initial: "Robert", l_name: "Man", address: "303 Springfield Ave", address1: "Apt D", city: "Lancaster", state: "North Carolina", zip: "97055", phone: "(803) 320-7672", cell_phone: "803-320-7672", fax: "", email: "billing@betazedsoftwaresolutionsinc.com", user_id: nil, source: "Call In", lead_source_id: nil, hot: true, comments: "asdfasdfasdf", active: true, created_at: "2015-12-10 08:52:21", updated_at: "2015-12-10 08:52:21">]> 

Answer 1

Queries like this where("hot=0 AND active=1") are depending on a certain database, because not all databases encode true and false as 1 or 0 .

Write your queries like this:

Lead.where(hot: false, active: true)

Answer 2

It is usually something stupid, if u say it works on dev. Try checking:

1. Connection to database, config
2. Display in view, maybe print debug of object
3. Result of query object, print debug

Temporarily activate debug and check logs for clues or dump the database and try the prod dump carefully in dev