code: public static JdbcExpert getExpert(DataSource ds) {
          log.info("Get Connection from DataSource for JdbcExpert, if you lock at here, check your database server and configure");
          Connection conn = null;
          try {
              conn = Trans.getConnectionAuto(ds);
              DatabaseMetaData meta = conn.getMetaData();
              String pnm = meta.getDatabaseProductName();
              String ver = meta.getDatabaseProductVersion();
              return getExpert(pnm, ver);
          }
          catch (Throwable e) {
              throw Lang.wrapThrow(e);
          }
          finally {
              Trans.closeConnectionAuto(conn);
          }
      }
docs: 针对一个数据源，返回其专属的 JdbcExpert
  
  @param ds
  数据源
  @return 该数据库的特殊驱动封装类
  
  @see org.nutz.dao.jdbc.Jdbcs#getExpert(String, String)