title: how to check a field is char or number?
body: <p>I have a NVARCHAR field in my table. (using Oracle 11g)</p>
  
  <p>I want check it has char data or number data.</p>
  
  <p>help me to write a select query. (using PL-SQL)</p>
  
  <p>I think I can write it with case, but I can't implement that. (I have no method for checking isChar and isNumber)</p>
  
  <pre><code>select
         case &lt;myField&gt;
             when &lt;isChar&gt; then
                 &lt;this is a char data&gt;
             when &lt;IsNum&gt; then
                 &lt;this is number data&gt;
         End
  from &lt;myTable&gt;
  </code></pre>