title: Convert varchar to float IF ISNUMERIC
body: <p>I have a column that contains characters and numbers</p>
  
  <pre><code>12
  13
  14
  19K/YR
  22
  </code></pre>
  
  <p>So the column type is varchar. But then I'm also doing some computations with this column, so I'm trying to convert the data to float if it is numeric.</p>
  
  <p>This gives me an error though:</p>
  
  <pre><code>SELECT CASE ISNUMERIC(QTY) 
           WHEN 1 THEN CAST(QTY AS float) 
           ELSE QTY 
         END AS test
  </code></pre>