title: Display zero by using count(*) if no result returned for a particular case
body: <p>I have a query like this that returns number of rows for each case in city .</p>
  
  <pre><code>select 
      case edition_id 
          when 6 then 'DELHI' 
          when 50 then 'AHMEDABAD' 
          when 4 then 'HYDERABAD' 
          when 25 then 'KOLKATA' 
          when 51 then 'BANGALORE' 
          when 5 then 'MUMBAI' 
          when 24 then 'CHENNAI' 
      end as CITY,
      count(*) as Total 
  from #tmptab1
  group by edition_id
  
  drop table #tmptab1
  </code></pre>
  
  <p>The result comes out to be like</p>
  
  <pre><code>CITY    Total
  MUMBAI  1
  DELHI   28
  CHENNAI 1
  KOLKATA 35
  AHMEDABAD 3
  </code></pre>
  
  <p>So if there is no rows returned from a city , that city is omitted in final result</p>
  
  <p>I want result as</p>
  
  <pre><code>CITY    Total
  MUMBAI  1
  DELHI   28
  CHENNAI 1
  KOLKATA 35
  AHMEDABAD 3
  BANGALORE 0 -- if no result from bangalore display zero.
  </code></pre>
  
  <p>How to do this ?</p>
  
  <p>I tried</p>
  
  <pre><code>case count(*)&gt;0 then count(*) else 0 end as Total 
  </code></pre>
  
  <p>but it does not work</p>