title: finding the mobile model and manufacturer with highest sales
body: <p>given two tables
  table 1 - sales_info</p>
  <ul>
  <li>salesid</li>
  <li>sales date</li>
  <li>imei</li>
  <li>price</li>
  <li>discount</li>
  <li>net amount</li>
  <li>customerid</li>
  <li>model_name</li>
  </ul>
  <p>table 2 -mobile_master</p>
  <ul>
  <li><p>imei</p>
  </li>
  <li><p>manufacturer</p>
  </li>
  <li><p>model_no</p>
  </li>
  <li><p>price</p>
  <p>pred sol</p>
  </li>
  </ul>
  <pre><code>    select manufacurer and model_name
      from sales_info INNER JOIN
           mobile_master
      where sales_info.model_name = mobile_master.model_name and mobile_master.model_name
      where (
      Select count(model_name)
      From Sales_info) as t
      Where t.rank = 1)
  </code></pre>
  <p>Find the model name and manufacturer with the highest sales .</p>