title: SQL Developer bind variables prompt: force string values
body: <p>I'm trying to use SQL Developer bind variables prompt to speed up query execution, but I'm not getting the desired output: looks like the values I put in get converted in number.</p>
  <p>Table description:</p>
  <pre><code>Nome               Null     Type         
  ------------------ -------- ------------ 
  NUM                NOT NULL VARCHAR2(13) 
  IS_OK                       NUMBER(1)
  </code></pre>
  <p>initial situation:</p>
  <p><a href="https://i.stack.imgur.com/X0kUx.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/X0kUx.png" alt="enter image description here" /></a></p>
  <pre><code>select NUM, IS_OK from numbers_table where NUM = cast(:dn as varchar2(13));
  
  NUM         |IS_OK |
  ------------|------|
  08331930078 |1     |
  </code></pre>
  <p><strong>working</strong> updates:</p>
  <p>1.</p>
  <pre><code>update numbers_table set IS_OK = 0 where NUM = 08331930078;
  </code></pre>
  <ol start="2">
  <li></li>
  </ol>
  <pre><code>update numbers_table set IS_OK = 0 where NUM = '08331930078';
  </code></pre>
  <p>ouput:</p>
  <pre><code>'1 row updated'
  </code></pre>
  <p><strong>non-working</strong> updates:</p>
  <p>1.</p>
  <pre><code>update numbers_table set IS_OK = 0 where NUM = :dn;
  </code></pre>
  <ol start="2">
  <li></li>
  </ol>
  <pre><code>update numbers_table set IS_OK = 0 where NUM = cast(:dn as varchar2(13));
  </code></pre>
  <p>output:</p>
  <pre><code>'0 rows updated'
  </code></pre>
  <p>Don't know what else can I do to force the value being parsed as a string.</p>
  <p>SQL Developer version 4.1.3.20</p>