title: Can we write case statement without having else statement
body: <p>I have this query:</p>
  
  <pre><code>select case when id=1 then 'A'
  when id=2 then 'B'
  end 
  from test
  </code></pre>
  
  <p>It is giving me o/p as</p>
  
  <blockquote>
    <p>Id<br>
    A<br>
    B<br>
    NULL<br>
    NULL<br>
    NULL</p>
  </blockquote>
  
  <p>I don't want to have <code>NULL</code> values in my output, I only want to compare in A and B, is it possible in case statement. </p>