title: case when blank check returning null
body: <p>I have following DB structure:</p>
  
  <p><img src="https://i.stack.imgur.com/7CC0B.png" alt="enter image description here"></p>
  
  <p>I wanted it in single column like:</p>
  
  <pre><code>Param
  
  -
  -
  AccountNo
  AccountNo DueDate
  </code></pre>
  
  <p>For this i written case when query:</p>
  
  <pre><code>select
  
  case when Param1 &lt;&gt;'' then 'Param1'+Param1 
  +case when Param2  &lt;&gt;'' then 'Param2'+Param2   
  +case when Param3  &lt;&gt;'' then 'Param3'+Param3  
  +case when Param4  &lt;&gt;'' then 'Param4'+Param4 
  +case when Param5  &lt;&gt;'' then 'Param5'+Param5
  
  end  
  end
  end
  end
  end
  'param'
  
  from IVR_PPMaster 
  </code></pre>
  
  <p>But this query is returning me all NULL values.</p>
  
  <p>Please help me to obtain result.</p>