title: Rails combine multiple activerecord relations
body: <p>I want to union multiple active record relation</p>
  
  <p>For example,</p>
  
  <pre><code>apple_companies = Company.where("name like ?","%apple%")
  banana_companies = Company.where("name like ?","%banana%")
  </code></pre>
  
  <p>I want to combine these two relation.</p>
  
  <p>not merge, merge is
       apple_companies.merge(banana_companies)
  =>     Company.where("name like ? and name like ?", "%apple%","%banana%")</p>
  
  <p>I want to
       Company.where("name like ? or name like ?", "%apple%","%banana%")</p>
  
  <p>afterward,</p>
  
  <p>I will code</p>
  
  <pre><code>companies = Company.none
  company_name_list.each do |name|
      like = "%"+name+"%"
      companies += Company.where("name like ?",like)
  end
  </code></pre>
  
  <p>but code which I wrote make companies to array.....</p>
  
  <p>So I cannot order and page to companies... :(</p>
  
  <p>thank you</p>