下面通过UPDATE语句将root用户的密码修改为mypwd2的语句中,正确的是 A: UPDATE mysql.user SET Password=PASSWORD('mypwd2') WHERE User='root' and Host='localhost'; B: UPDATE mysql.users SET Password=PASSWORD('mypwd2') WHERE User='root' and Host='localhost'; C: UPDATE mysql.users SET Password=PASSWORD('mypwd2') WHERE User='root' OR Host='localhost'; D: UPDATE mysql.user SET Password=PASSWORD('mypwd2') WHILE User='root' OR Host='localhost';

默认情况下，root用户属于以下哪个用户组？ A: user B: admin C: root D: system

哪个能实现删除用户的命令( )。 A: delete from MySQL.user B: delete user C: drop root D: truncate user

以下程序输出结果为( )$conn = mysqli_connect('localhost','root','root','test');$result = mysqli_query($conn,'select * from user');$data = mysqli_num_rows($result);echo $data A: 输出user表所有记录 B: 输出user表记录总数 C: 输出user表第一条数据 D: 输出user表最后一条数据

默认情况下,root用户CREATE USER创建的用户具有权限