title: How to prevent a character field containing numbers from converting to numeric?
body: <p>How to prevent a varchar field containing numbers from converting to numeric in oracle sql?  This occurs only if used in a join.</p>
  <p>Example</p>
  <p>a varchar column named tbl1.col1 contains '012345'</p>
  <pre><code>select tbl1.col1 from tbl1 
  
  012345
  -- result OK
  </code></pre>
  <p>used in a join:</p>
  <pre><code>select tbl1.col1 from tbl1 inner join tbl2 on tbl1.key = tbl2.key  
  
  12345
  -- result not OK, converted to numeric.
  </code></pre>