ORACLE subtraction from user defined variable
<p>what I'm trying to accomplish is to subtract 1 month from user given date variable. My code in where conditions is as following:</p>

<pre><code>CONDITION &gt;= to_char(add_months('&amp;datum_od', 1), 'dd.mm.yyyy')
</code></pre>

<p>I am getting "ORA-1843: not a valid month" error. </p>

<p>Could you guys please help me out here? </p>