服务器发生错误时所提供的唯一错误码，打印在 Proxy 后端或 JDBC 启动日志中。

    错误码错误信息
    SPI-00001No implementation class load from SPI ‘%s’ with type ‘%s’.
    DATA-SOURCE-00001Data source ‘%s’ is unavailable.
    PROPS-00001Properties convert failed, details are: %s.
    PROXY-00001Load database server info failed.