D. A B C C
正确答案:D
8. 把s_emp月薪超过1000的员工列出来的SQL语句是?
A.
select last_name,salary from s_emp where salary>1000
B.
select name,salary from s_emp where salary>1000
C.
select name,salary from s_emp where salary<1000
D. select last_name,salary from s_emp where salary<1000 正确答案:A
9.
阅读以下代码: class Human{ public:
void move(){
cout<<\ }
virtual void attack(){
cout<< \ } };
class FootMan : public Human{ public:
void move(){
cout << \ }
virtual void attack(){
cout << \
} };
int main() {
Human* ph = new FootMan; ph->move(); ph->attack(); delete ph; }
请问执行的结果是?
A. moving和FootMan attack B. moving和attack
C. action和FootMan attack D. action和attack 正确答案:A
10. 在建表时,经常需要用到约束,请问下面哪个不是常见约束?
A. 主键 B. 非空 C. 回滚 D. 外键 正确答案:C
11. 假设Base类派生了Derived类,FileException和MemoryException都是异常类,则以下虚函数的声明中哪些可以构成正确的覆盖?
A.
Base* Base::copy (Base*);
Base* Derived::copy (Derived*);
B.
Base* Base::copy (Base* = NULL) throw (FileException, MemoryException);
Derived* Derived::copy (Base*) throw (MemoryException);
C.
bool Base::print (ostream&); void Derived::print (ostream&);
D.
void Base::eval (void) const; void Derived::eval (void);
正确答案:B
12. 下面分组语句正确的是?
A. Select name,dept_id from s_dept d,s_emp e where dept_id=id group by dept_id; B. Select e.name,dept_id from s_dept d,s_emp e where dept_id=d.id group by dept_id; C. Select e.name,dept_id from s_dept d,s_emp e where dept_id=d.id group by dept_id; D. Select max(name),dept_id from s_dept d,s_emp e where dept_id=d.id group by dept_id; 正确答案:D
13. 已知数据库中有员工表s_emp和部门表s_dept,具体字段如下: 员工表字段介绍:
ID 员工编号 LAST_NAME 员工姓 FIRST_NAME 员工名 USERID 用户编号 START_DATE 入职日期
COMMENTS 员工备注信息 MANAGER_ID 员工的领导ID TITLE 员工的职位 DEPT_ID 部门的编号 SALARY 员工的月薪 COMMISSION_PCT 提成 部门表的字段介绍:
ID 部门编号 NAME 部门名 REGION_ID 地区编号
注:以下所有数据库相关题目,均使用这两个表
把s_emp表中的每个人的全名和工资列出来的SQL语句是?
A.
select first_name|last_name ,salary from s_emp
B.
select first_name||last_name ,salary from s_emp
C.
select first_name|last_name ,salary from emp
D. select first_name||last_name ,salary from emp 正确答案:B
14.
阅读如下C++代码: bool b = true; b = 3; int x = 10; x += b;
cout << x << endl; 该代码的输出为:
A.
11
B. 13 C. 10 D. 编译错误 正确答案:A
15.
在大型项目设计时,类的继承层次会相应比较复杂,假设有如下类的继承关系: class A{virtual void m(){}}; class B : public A{}; class C : public B{}; class D : public B{}; 现有一变量的定义如下: A* p = new B;
那么,下列表达式的结果为逻辑真(true)的是:
A. typeid(*p) == typeid(A); B. typeid(*p) == typeid(B); C. typeid(*p) == typeid(C); D. typeid(*p) == typeid(D); 正确答案:B
16.
以下代码 class A { public:
virtual ~A (void) {} private: char m_c; };
class B : virtual public A {}; class C : virtual public A {}; class D : public B, public C {}; int main (void) {
cout << sizeof (A) << ' ' << sizeof (B) << ' ' << sizeof (C) << ' ' << sizeof (D) << endl; return 0; }
的输出是?
A. 8 12 12 16 B. 8 12 12 24 C. 8 8 8 16 D. 1 1 1 2 正确答案:A
17. 统计每个部门的人数的SQL语句是?
A. select dept_id,max(dept_id) from s_emp group by dept_id B. select dept_id,avg(dept_id) from s_emp group by dept_id