code: public static void update(String sql, Object... arg) {
          Connection connection = JDBCUtils.getConnection();
          PreparedStatement ps = null;
          try {
              ps = connection.prepareStatement(sql);
              for (int i = 0; i < arg.length; i++) {
                  ps.setObject(i + 1, arg[i]);
              }
              ps.executeUpdate();
          } catch (SQLException e) {
              e.printStackTrace();
          }
  
          JDBCUtils.release(ps, connection);
      }
docs: 传入的SQL语句只能是INSERT,DELETE,UPDATE和DDL语句
  
  @param sql 相应SQL语句
  @param arg 传入的占位符的参数