title: Show me the numbers and return Null in place of text
body: <p>I'm wishing to get the data shown in coln B when using coln A - in essence show me the numbers and return Null in place of text using SQL Server 2016.</p>
  
  <pre><code>Coln A     
  123       
  qw       
  Null        
  456      
  aa
  
  Coln B   
  123   
  Null     
  Null    
  456    
  Blank
  </code></pre>
  
  <p>Thanks in advance for your help.</p>