In Access, you can only create duplicate indexes for primary keywords.

Which of the following citation indexes was not originally published by the Institute for Scientific Information (ISI)?

已知,存在 QueryRunner对象 runner , SQL语句: String sql = "select * from user where id=?"; 下面操作中,能实现查询指定记录的选项是() A: User user=(User)runner.query(sql, new BeanListHandler(User.class), new Object[]{id}); B: User user=(User)runner.query(sql, new BeanHandler(User.class)); C: User user=(User)runner.query(sql, new BeanListHandler(User.class), id); D: User user=(User)runner.query(sql, new BeanHandler(User.class), new Object[]{id});

request.setAttribute("user","svse");session.setAttribute("user","bob");使用{user}则显示( )

在请求中没有包含名为user的参数时，使用如下语句{user}，则会出现（）。 A: 编译报错 B: 运行出错 C: null D: 什么都没有