Paradox/Toolbox.php
public function generateBindingParameter($parameter, $userParameters)
    {
        $userParameters = array_keys($userParameters);

        while (in_array($parameter, $userParameters)) {

            $characters = '0123456789abcdefghijklmnopqrstuvwxyz';

            for ($i = 0; $i < 7; $i++) {
                $parameter .= $characters[rand(0, strlen($characters) - 1)];
            }
        }

        return $parameter;
    }
public function generateBindingParameter($parameter, $userParameters)
    {
        $userParameters = array_keys($userParameters);

        while (in_array($parameter, $userParameters)) {

            $characters = '0123456789abcdefghijklmnopqrstuvwxyz';

            for ($i = 0; $i < 7; $i++) {
                $parameter .= $characters[rand(0, strlen($characters) - 1)];
            }
        }

        return $parameter;
    }
This generates a binding parameter for filtering so that it does not clash with any user defined parameters.
@param  array  $userParameters An array of binding parameters.
@return string