title: Join Two Tables and then Group By
body: <p>I have two tables in a MySql database:</p>
  
  <pre><code>COUNTRY
  ---------------
  id, 
  country_name
  </code></pre>
  
  <p>and  </p>
  
  <pre><code>CITY 
  ---------------
  c_id, 
  city_name, 
  id
  </code></pre>
  
  <p>The Country is a parent table of city: <code>country.id</code> = <code>city.id</code>  </p>
  
  <p>I want to display the following:</p>
  
  <pre><code>Country_name   count of cities 
  ------------------------------
  USA            333  
  UAE            293  
  ....  
  </code></pre>
  
  <p>*Show all either if country is null or city is null.</p>