Paris,France
London,Britain
Berlin,Germany
Brussels,Belgium
第1题:
下面对 union 的描述正确的是( )
A.union 只连接结果集完全一样的查询语句
B.union 可以连接结果集中数据类型个数相同的多个结果集
C.union 是筛选关键词,对结果集再进行操作
D.任何查询语句都可以用 union 来连接
第2题:
union和union all有什么不同?
查出比经理薪水还高的员工信息:
Drop table if not exists employees;
create table employees(id int primary key auto_increment,name varchar(50)
,salary int,managerid int references employees(id));
insert into employees values (null,'zxx',10000,null), (null,'lhm',15000,1
),(null,'flx',9000,1),(null,'tg',10000,2),(null,'wzg',10000,3);
Wzg 大于flx,lhm 大于zxx
select e.* from employees e,employees m where e.managerid=m.id and e.sala
ry>m.salary;
第3题:
According to labor law, which of the following management actions are prohibited during a union organizing drive?
A . Forbidding employees from distributing union literature in working areas
B . Implementing previously scheduled pay raises
C . Forbidding unions from soliciting workers during working hours
D . Circulating anti-union petitions
E . All of the above
第4题:
Which of the following is not true of Britain.s foreign trade?()
AThe value of Britain.s exports of goods usually exceeds the value of its imports.
BThe value of Britain.s imports of goods usually exceeds the value of its exports.
CManufactured goods now account for about 85%of British imports and about 80%of its exports.
DMost of the United Kingdom.s trade is with other developed countries,especially other members of the European Union.
第5题:
第6题:
union和union all有什么不同?
查出比经理薪水还高的员工信息:
Drop table if not exists employees;
create table employees(id int primary key auto_increment,name varchar(50)
,salary int,managerid int references employees(id));
insert into employees values (null,'zxx',10000,null), (null,'lhm',15000,1
),(null,'flx',9000,1),(null,'tg',10000,2),(null,'wzg',10000,3);
Wzg 大于flx,lhm 大于zxx
select e.* from employees e,employees m where e.managerid=m.id and e.sala
ry>m.salary;
第7题:
有如下程序段#include "stdio.h"typedef union{ long x[2]; int y[4]; char z[8];}atx;typedef struct aa { long x[2]; int y[4]; char z[8];} stx;main(){ printf("union=%d,struct aa=%d\n",sizeof(atx),sizeof(stx));}则程序执行后输出的结果是A.union=8,struct aa=8 B.union=8,struct aa=24C.union=24,struct aa=8 D.union=24,struct aa=24
第8题:
What can we learn about the Mayan calendar?
A. It was based on the European calendars.
B. It was better than European calendars.
C. It was as accurate as European calendars.
D. It was copied by European calendars.
第9题:
The European Union(EU)is an organization of 15()that promotes cooperation among its members.A.European countries
AEuropean countries
Bdeveloped countries
CWestern European countries
DSouthern European countries
第10题:
Which of the following is not true of the European Union?()
AThe United States is also a member of the EU.
BThe members of the EU cooperate in many areas,including politics and economics.
CThe EU is a major economic unit.
DThe combined value of the union.s imports and exports is greater than that of any single country in the world.