Multi where condition Put on wso2 integration studio - wso2

Question

I have SQL Update statement with optional filter (multi where condition ) that i would like to exposed as an
Api
the problem is that I need to put where parameters optional :
for example the user will be able to search by id only or by id and age or by id and age and note
tried using the mediator script
<resource methods="PUT" uri-template="modif">
<inSequence>
<script language="js"><![CDATA[var queryString = "WHERE ";
var AND =" AND ";
var age = mc.getProperty('query.param.age');
var note = mc.getProperty('query.param.note');
queryString += (age)? " age=" + age+" " + AND : " ";
queryString += (note)? " note=" + note+" " + AND : "";
queryString =queryString.toString();
var n = queryString.lastIndexOf(AND);
mc.setProperty('queryString',queryString.slice(0, n));]]></script>
<property expression="get-property('queryString')" name="uri.var.queryString" scope="default" type="STRING"/>
<payloadFactory media-type="json">
<format>{
"_putmodifstudent": {
"id" : $id,
"nom": "$nom",
"prenom:"$prenom",
"whereage":$age,
"wherenote":"$note"
}
}</format>
<args/>
</payloadFactory>
<call>
<endpoint>
<http method="put" statistics="enable" trace="enable" uri-template="http://ITMTNF3RRJSJ:8290/services/studenttest/modifstudent">
<suspendOnFailure>
<initialDuration>-1</initialDuration>
<progressionFactor>-1</progressionFactor>
<maximumDuration>0</maximumDuration>
</suspendOnFailure>
<markForSuspension>
<retriesBeforeSuspension>0</retriesBeforeSuspension>
</markForSuspension>
</http>
</endpoint>
</call>
<respond/>
</inSequence>
<outSequence/>
<faultSequence/>
</resource>
My sql statement in dataservice
<sql>UPDATE etudiant SET nom =?, prenom =?, age =?, note =? where id =? and age =? and note =?</sql>