首页
普通专升本
成人高考
学位英语
在线刷题
最近学习
最近学习课程
最强大脑 · 3天挑战极限记...
副标题副标题副标题副
最强大脑 · 3天挑战极限记...
副标题副标题副标题副
您现在位置：
模拟考场
>
湖北自学考试
>
专业课
>
数据库系统原理
>
浏览试题
[单选题]
下面不是关系数据模型的性质的是( )
A
A．关系的每个属性是不可分割的 B．关系模型的查询效率比非关系模型高C．关系中不允许出现重复元组 D．关系是一个集合，因此没有行序
收藏
查看答案
参考答案
试题答案：
B
答案解释：
相关题目
在对象联系图中，如果从A到B有双线箭头，则表示B是A的（）
完成关系模式设计是在数据库设计的( )
38．根据题36给出的关系模式，实现下列操作：用SQL语言查询由姓吴的饲养员饲养的所有动物的个数
20．在基本表不需要时，撤销基本表的语句是_______。
修改数据库模式的权限不包括（）
数据库应用程序的编写是基于三级模式结构中的( )
XY能用FD推理规则推出的充分必要条件是( )A.B.C.D.
29．简述SQL语句定义游标的句法。
23.存储过程可以增强代码的可重用性，提高________。
35．简述驱动程序管理器的主要功能。
热门试题
1.
17.制定幼儿园课程计划应遵循全面性原则、统整性原则、灵活性原则和（)
2.
3.《春秋》的语言特点是
3.
30．企业的外部社会环境包括
4.
4. British Columbia is the third largest Canadian province, both in area and population. It is nearly 1 1/2 times as large as Texas, and extends 800 miles (1,280 km) north from the United States' border. It includes Canada's entire west coast and the islands just off the coast.Most of British Columbia is mountainous, with long, rugged (崎岖的) ranges running north and south. Even the coastal islands are the remains of a mountain range that existed thousands of years ago. During the last Ice Age, this range was scoured (冲刷) by glaciers (冰河) until most of it was beneath the sea. Its peaks now show as islands scattered along the coast.The southwestern coastal region has a humid mild marine climate. Sea winds that blow inland from the west are warmed by a current of warm water that flows through the Pacific Ocean. As a result, winter temperatures average above freezing and summers are mild. These warm western winds also carry moisture from the ocean.Inland from the coast, the winds from the Pacific meet the mountain barriers of the coastal ranges and the Rocky Mountains. As they rise to cross the mountains, the winds are cooled, and their moisture begins to fall as rain. On some of the western slopes almost 200 inches (500 cm) of rain fall each year.More than half of British Columbia is heavily forested. On mountain slopes that receive plentiful rainfall, huge Douglas firs (冷杉) rise in towering columns. These forest giants often grow to be as much as 300 feet (90 m) tall, with diameters up to 10 feet (3 m). More lumber is produced from these trees than from any other kind of trees in North America. Hemlock (铁杉), red cedar (雪松), and balsam fir are among the other trees found in British Columbia.36. With which aspect of British Columbia is the passage primarily concerned?____A. Its people. B. Its culture. C. Its geography. D. Its history.
5.
各种产品成本计算基本方法，其成本计算对象是不同的。所以，所有方法的费用最终承担者也不同。
热门试卷
成人高考专升本《政治》模拟试卷
去做题
已有3416做题
2020年湖北成人高考专升本政治模拟试题三
去做题
已有2213做题
成人高考专升本政治考试模拟试题及答案(1)
去做题
已有1898做题
湖北成考专升本政治真题（2021年）
去做题
已有1355做题
成人高考高起点语文考试高分突破试题及答案四
去做题
已有1194做题
