phpmyadmin / sql-parser

        if ($this->values != NULL && count($this->values) > 0) {

            $ret .= ' VALUES ' . ArrayObj::build($this->values);

        } elseif ($this->set != NULL && count($this->set) > 0) {

            $ret .= ' SET ' . SetOperation::build($this->set);

        } elseif ($this->select != NULL && count($this->select) > 0) {

            $ret .= ' ' . $this->select->build();

        }

            $ret .= ' ' . $this->select->build();

        }

        if ($this->onDuplicateSet != NULL && count($this->onDuplicateSet) > 0) {

            $ret .= ' ON DUPLICATE KEY UPDATE ' . SetOperation::build($this->onDuplicateSet);

        }

        return $ret;