title: SQL How to update data if the value given is not null/empty
body: <p>I have a table of users
  and I want users to update some of their details (data), but if a user decided not insert a value and send it empty, I want the data   to remain with same value.</p>
  
  <p>This doesn't work for me at all if I insert - </p>
  
  <pre><code>exec UpdateAboutMe '','','',21  To this proc:
  </code></pre>
  
  <p><img src="https://i.stack.imgur.com/8YkUW.png" alt="this is the proc"></p>
  
  <p>I can't copy the code to here: "Your post appears to contain code that is not properly formatted as code" I tried for a half an hour to change it and the same message comes on and on - I uploaded a screenshot</p>
  
  <p>It erased the user data and its empty.</p>
  
  <p><img src="https://i.stack.imgur.com/XPJlp.png" alt="row affected"></p>
  
  <p>I tried so many ways, not to say million in one day/night
  and didn't succeed.</p>
  
  <p>what is the right way ?
  To make it clear this is the opposite of what I want  - </p>
  
  <pre><code>    SET @AboutMe= IsNull(@AboutMe, [About_me])
  </code></pre>
  
  <p>So if @AboutMe sent empty, [About_me] will not cleared/erased.
  Thanks.</p>