code: protected final function getSchemaSQLs($toVer, $fromVer = '0.0.0') {
  		$sqls    = [];
  		$sqlFile = MODULES_PATH . $this->dirname . DS . 'schema.sql.php';
  		if (is_file($sqlFile)) {
  			$tables = [];
  			@include $sqlFile;
  			if (!empty ($tables)) {
  				foreach ($tables as $ver => $var) {
  					if ($var && version_compare($ver, $toVer, '<=') && version_compare($ver, $fromVer, '>')) {
  						$sqls = array_merge($sqls, (array)$var);
  					}
  				}
  			}
  		}
  
  		return $sqls;
  	}
docs: 加载SQL语句
  
  @param string $toVer
  @param string $fromVer
  
  @return array