试题与答案

Visual FoxPro的“参照完整性”中“插入规则”包括的选择是( )。A.级联

题型:单项选择题

题目:

Visual FoxPro的“参照完整性”中“插入规则”包括的选择是( )。

A.级联和忽略

B.级联和删除

C.级联和限制

D.限制和忽略

答案:

参考答案:D

解析: 参照完整性与表之间的关联有关,它的大概含义是:当插入、删除或修改一个表中的数据时,通过参照引用相互关联的另一个表中的数据,来检查对表的数据操作是否正确。参照完整性规则包括更新规则、删除规则和插入规则。 插入规则规定了当在了表中的插入记录时,是否进行参照完整性检查:如果选择“限制”,若父表中没有相匹配的连接字段值,则禁止插入子记录;如果选择“忽略”,则不作参照完整性检查,即可以随意插入子记录。

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题型:阅读理解

Five years ago, David Smith wore an expensive suit to work every day. “I was a clothes addict,” jokes. “I used to carry a fresh suit to work with me so I could change if my clothes got wrinkled.” Today David wears casual clothes---khaki pants and sports shirt---to the office. He hardly ever wears necktie. “I’m working harder than ever,” David says, “and I need to feel comfortable.”

More and more companies are allowing their office workers to wear casual clothes to work in the United States. The change from formal to casual office wear has been gradual. In the early 1990s, many companies allowed their employees to wear casual clothes on Friday (but only on Friday). This became known as “dress-down Friday” or “casual Friday.” “What started out as an extra one-day-a-week benefit for employees has really become an everyday thing,” said business consultant Maisly Jones.

Why have so many companies started allowing their employees to wear casual clothes? One reason is that it’s easier for a company to attract new employees if it has a casual dress code. “A lot of young people don’t want to dress up for work,” says the owner of a software company, “so it’s hard to hire people if you have a conservative dress code.” Another reason is that people seem happier and more productive when they are wearing comfortable clothes. In a study conducted by Levi Strauss and Company, 85 percent of employers said that they believe that casual dress improves employee morale. Only 4 percent of employers said that casual dress has a negative impact on productive. Supporters of casual office wear also argue that a casual dress code helps them save money. “Suits are expensive, if you have to wear one every day,” one person said. “For the same amount of money, you can buy a lot more casual clothes.”

小题1:David Smith refers to himself as having been “a clothes addict” because_______.

A.he often wore khaki pants and a sports shirt

B.he couldn’t stand a clean appearance

C.he wanted his clothes to look neat all the time

D.he didn’t want to spend much money on clothes小题2:David Smith wears casual clothes now, because________

A.they make him feel at ease when working

B.he cannot afford to buy expensive clothes

C.he looks handsome in casual clothes

D.he no longer works for any company小题3:According to this passage, which of the following statements is FALSE?

A.Many employees don’t like a conservative dress code.

B.Comfortable clothes make employees more productive

C.A casual clothes code is welcomed by young employees

D.All the employers in the U.S are for casual office wear.小题4:In this passage, the following advantages of casual office wear are mentioned EXCEPT_______.

A.saving employees’ money

B.making employees more attractive

C.improving employees’ motivation

D.making employees happier

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