protected function getUpdateQueries()
    {
        $schema = new SchemaTool($this->em);

        $metadatas = $this->em->getMetadataFactory()->getAllMetadata();

        // Insure the name of altered tables are quoted according to the platform
        $this->em->getEventManager()->addEventListener(Events::onSchemaAlterTable, $this);

        $sqls = $schema->getUpdateSchemaSql($metadatas, true);

        return $sqls;
    }