title: SQL UPDATE SET one Column to another value and change value in same step
body: <p>Take the following update statement.</p>
  
  <pre><code>UPDATE  TABLE_1
  SET     Units2 = ABS(Units1)
          ,Dollars2=ABS(Dallars1)
          ,Units1 =0
          ,Dollars1 =0
  WHERE Units1 &lt; 0
  AND   Dollars2 = 0
  </code></pre>
  
  <p>Here are my questions,</p>
  
  <p>1) Is this legal?  It parses and it "seems" to work (on the test table), but will it always work or am I just picking the right records to review.</p>
  
  <p>2) is there a better way to do this.</p>
  
  <p>Thanks,</p>