问题 填空题

设有图书管理数据库:
图书(总编号C(6),分类号C(8),书名C(16),作者C(6),出版单位C(20),单价N(6,2))
读者(借书证号C(4),单位C(8),姓名C(6),性别C(2),职称C(6),地址C(20))
借阅(借书证号C(4),总编号C(6),借书日期D(8))

对图书管理数据库,查询所有已借出的书名。请对下面的SQL语句填空:
SELECT 书名 FROM 图书;
WHERE 总编号______

答案

参考答案:IN(SELECT总编号FROM借阅)

解析:[知识点] 关系数据库标准语言SQL/SQL的数据查询功能/嵌套查询
[评析] 查询要使用SELECT命令,本题是嵌套查询。已借出图书的总编号信息存储在借阅表中,而书名信息存储在图书表中。由内层查询:
SELECT总编号FROM借阅
获得的结果是借出图书的总编号值的集合,外层查询的结果只列出在内层查询集合中的总编号所对应的书名,即外层查询的结果依赖于内层查询的结果。
由于内层查询结果是一个集合,所以,要用“IN”运算符,不能用“=”运算符。内层查询必须用一对圆括号括起来。

阅读理解

阅读短文,根据其内容,选择最佳选项完成下列各题。(10分)

Paragraph 1:     Scientists have learned a lot about the kinds of food people need. They say that there are several kinds of food that people should eat every day. They are: (1) green and yellow vegetables of all kinds; (2) citrus(柑桔) fruits and tomatoes; (3) potatoes and other fruits and vegetables; (4) meat of all kinds, fish and eggs; (5) milk and foods made from milk; (6) bread or cereal(谷物), rice is also in this kind of food; (7) butter, or something like butter.

Paragraph 2:    People in different places of the world eat different kinds of things. Foods are cooked and eaten in many different kinds of ways. People in different countries eat at different times of the day. In some places people eat once or twice a day; in other countries people eat three or four times. Scientists say that none of the differences is really important. It doesn’t matter whether foods are eaten raw or cooked. It doesn’t matter if a person eats dinner at 4 o’clock in the afternoon or at 11 o’clock at night. The important thing is what you eat every day.

Paragraph 3:   There are two problems, then, in feeding the large number of people on earth. The first is to find some ways to feed the world’s population so that no one is hungry. The second is to make sure that people everywhere have the right kinds of food to make them grow to be strong and healthy.

小题1:From the first paragraph we know noodles belong to a kind of ______ food.

A.vegetable

B.fruit

C.meat

D.cereal小题2:According to the scientists, which of the following groups is the healthiest for your lunch?

A.chicken, apples, cereal, cabbages

B.potatoes, rice, bread, carrots

C.oranges, bananas, fish, tomatoes

D.beef, pork, fish, milk小题3:People in different places of the world ______.

A.have the right kinds of food to eat

B.cook their food in the same way

C.have their meals at the same time

D.eat food in different ways小题4:Which of the following is NOT true?

A.People in some places don’t have enough to eat.

B.There are too many people in the world.

C.One of the problems is that no one is hungry.

D.The scientists are trying to make people grow to be strong and healthy.小题5: If there is Paragraph 4, what do you think is going to be talked about?

A.When people eat their meals.

B.What to do with the two problems.

C.How to cook food in different ways.

D.Why people in different places eat different kinds of food.

单项选择题