title: How to use conditional operator in sql
body: <p>What I am trying to retrieve is the contact number. I have a relation called BusinessDetails and the fields are <code>Name</code>,<code>Description</code>, <code>PhoneNum</code>, <code>MobileNum</code>. Case of contact number are as follows:</p>
  
  <ol>
  <li>I can have both MobileNum and PhoneNum.</li>
  <li>I can have any one of them</li>
  <li>I can't have both of them</li>
  </ol>
  
  <p>I am trying this piece of sql select statement and it is quite good when there are both number. but in the <code>2</code> and <code>3</code> case there is unnecessary comma associated with it. My sql is</p>
  
  <pre><code>   SELECT Business.PhoneNum+','+Business.MobileNum AS ContactNumber 
       FROM dbo.BusinessDetails AS Business
  </code></pre>
  
  <p>Can some body help me out for removing comma in 2nd and 3rd case?</p>