中国信保笔试题目

填空题

1、关系代数以集合代数为基础运算，基本操作是并、差、笛卡儿积、投影和选择。规范化理论

中分解关系模式主要是消除多余的数据相关性。

2、数字签名常用公开密钥加密方法。发送者签名使用的'密钥为发送者的公钥，

常用的加密算法有 Hash 签名、DSS 签名、RSA 签名。

3、Internet 实现组播，传输层协议为组播地址解析协议(MARS：Multicast Address Resolution Server)

4、完整性约束:

单个关系上的约束

not null

unique

check

参照完整性

断言

函数依赖

简答题

MVC 模式及其作用，列出至少两种目前流行的 MVC 组件。

六、数据库设计

1、建表

create table Company(companyName varchar2(30), id number(4) primary key);

create table EmployeeHired(id number(4), numberHired number(4),

FiscalYear number(4), FiscalQuarter number(4),

foreign key(id) references Company(id),

primary key(id, FiscalYear, FiscalQuarter));

2、插入数据

insert into Company values('Microsoft', 1);

insert into Company values('IBM', 2);

insert into Company values('HP', 3);

insert into Company values('Nortel', 4);

insert into EmployeeHired values(1, 1, 2007, 1);

insert into EmployeeHired values(1, 3, 2007, 3);

insert into EmployeeHired values(1, 3, 2008, 2);

insert into EmployeeHired values(2, 2, 2007, 2);

insert into EmployeeHired values(2, 4, 2007, 4);

insert into EmployeeHired values(2, 2, 2008, 1);

insert into EmployeeHired values(3, 5, 2008, 1);

insert into EmployeeHired values(3, 10, 2008, 2);

insert into EmployeeHired values(4, 3, 2008, 3);

insert into EmployeeHired values(4, 6, 2008, 4);

3、在表 Company 中加入一列 Address varchar2(40);

alter table Company

add Address varchar2(40);

4、将2008年招员工人数超过3人的公司名称和总人数查出，按人数降序排列;

select companyName, sum(numberHired) as sum

from Company c, EmployeeHired e

where = and FiscalYear = 2008

group by , companyName

having sum(numberHired) > 3

order by sum desc;