Performing webservice calls using validation

[Guido1982]

So this is not working for me. I refactored my webservice call from:

PHP Code:

$client->doCreate('Assets', $params); 


to

PHP Code:

$client->doInvoke('CreateWithValidation', array('elementType' => 'Assets', 'element' => json_encode($params))); 


But that just created the asset, while I was using a duplicate serial no., which I prohibit in my custom validation function:

PHP Code:

function isUniqueSerial($fieldname, $fieldvalue, $params, $entity) {
    global $adb;
    $recordid = $entity['record'] == '' ? 0 : $entity['record'];
    $r = $adb->query("SELECT vtiger_assets.serialnumber
                        FROM vtiger_assets
                        INNER JOIN vtiger_crmentity ON vtiger_assets.assetsid = vtiger_crmentity.crmid
                        WHERE vtiger_assets.product = {$entity['product']}
                        AND vtiger_assets.serialnumber = '{$entity['serialnumber']}'
                        AND vtiger_assets.assetsid != {$recordid}
                        AND vtiger_crmentity.deleted = 0");
    return $adb->num_rows($r) > 0 ? false : true;
}