下面选项中,用于在删除存储过程时,检测存储过程是否存在的关键字是
A. IF EXISTS
B. HAS EXISTS
C. AS EXISTS
D. IS EXISTS
下面声明一个名为cursor_student的游标,语法格式正确的是
A. CURSOR cursor_student OF select s_name,s_gender FROM student;
B. CURSOR cursor_student FOR select s_name,s_gender FROM student;
C. DECLARE cursor_student CURSOR FOR select s_name,s_gender FROM student;
DECLARE cursor_student CURSOR OF select s_name,s_gender FROM student;
MySQL中,预设的拥有最高权限的超级用户的用户名为()
A. test
B. administrator
C. DBA
D. root
影响计算机系统安全的因素包括( )
A. 计算机病毒
B. 系统故障的风险
C. 内部人员道德风险
D. 以上都是