使用 SQL 语句将学生表 S 中年龄（AGE）大于 30 岁的记录_爱下问搜题

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问题单项选择题

使用 SQL 语句将学生表 S 中年龄（AGE）大于 30 岁的记录删除，正确的命令是______。

A．DELETE FOR AGE>30

B．DELETE FROM S WHERE AGE>30

C．DELETE S FOR AGE>30

D．DELETE S WHERE AGE>30

答案

参考答案：B

解析：SQL 从表中删除数据的命令格式如下：DELETE FROM tableName [WHERE Condition]这里的 FROM 指定从哪个表中删除数据。WHERE 指定被删除的记录所满足的条件。如果不使用WHERE 子句，则删除该表中的所有记录。DELETE FOR为Visual FoxPro删除记录的命令，且限定被删除记录的表处于当前状态。

问答题简答题

列出5项产前灌肠的禁忌证。

完形填空

Do you feel upset when you hear that your school might not allow cell phones? Do you break into a cold sweat when your cell phone battery(电池) dies? If you        live without your cell phone, you might have a       .
A recent study found that some people could be        to their cell phones. The study was conducted at Staffordshire University in England. About 40 percent of students        said they couldn’t do without their cell phones. About 90% said they took their        with them everywhere. One third of students surveyed said they used cell phones to        themselves up.
The study also asked students 18 to 25 questions designed to        addictive behavior. The results found that one in six cell phone users have a lot in        with gambling addicts (赌瘾). Some people said they sometimes lied about their cell phone use.        admitted stealing to pay for their cell phone habit.
Dr David Sheffield,        conducted the study, said he wasn’t surprised by the       . “Students use their phones       , and this has both positive        such as staying in touch with friends and family, and negative ones too, such as        costs and social costs,” he told Weekly Reader. “The most        finding was that a number of people reported they had        a relationship or job because they spent too much time on mobile phones .”
     part of the study, some students agreed to take a        from their cell phones. After three phone-free days, students reported feeling less        about their daily lives. That might be a        reason to hang up the phone!

A．discoveries

B．explorations

D．experiments

A．interesting