title: How do I stop a comma being added using CONCAT_WS if column is empty
body: <pre><code>SELECT CONCAT_WS(',', Col1, Col2, Col3 ) AS combined FROM table_name
  </code></pre>
  
  <p>Currently if I have fields Col1 = 'hello', Col2 = 'Bye', Col2 = 'Goodnight'</p>
  
  <p>The above select statement would return hello,Bye,Goodnight which is fine.</p>
  
  <p>What if any of the Cols where blank. A Comma would still be added. like hello,,Goodnight.</p>
  
  <p>Is there a way to say if the Col is empty then ignore it? (This is MySQL)</p>