title: Determine if a Varchar field has a Numeric entry
body: <p>I've got a field in a table that has a DataType of varchar(10).  This field contains numeric values that are formatted as a varchar, for the sole purpose of being used to join two tables together.  Some sample data would be:</p>
  
  <pre><code>AcctNum        AcctNumChar   
  2223333          2223333   
  3324444          3324444
  </code></pre>
  
  <p>For some records, the table sometimes thinks this field (AcctNumChar) is numeric and the join doesn't work properly.  I then have to use an Update statement to re-enter the value as a varchar.</p>
  
  <p>Is there any way to determine whether or not the field has a varchar or numeric value in it, using a query?  I'm trying to narrow down which records are faulty without having to wait for one of the users to tell me that their query isn't returning any hits.</p>