title: SQL IsNumeric not working
body: <p>The reserve column is a varchar, to perform sums on it I want to cast it to a deciaml.
  But the SQL below gives me an error</p>
  
  <pre><code>select
  cast(Reserve as decimal)
  from MyReserves
  </code></pre>
  
  <p>Error converting data type varchar to numeric.</p>
  
  <p>I added the isnumeric and not null to try and avoid this error but it still persists, any ideas why?</p>
  
  <pre><code>select
  cast(Reserve as decimal)
  from MyReserves
  where isnumeric(Reserve ) = 1
  and MyReserves is not null
  </code></pre>