关于SQL的超联接查询，说法错误的是A．在SQL中可以进行内部联接_爱下问搜题

搜题请搜索小程序“爱下问搜题”

问题单项选择题

关于SQL的超联接查询，说法错误的是

A．在SQL中可以进行内部联接、左联接、右联接和全联接

B．SQL的超联接运算符“*＝”代表左联接，“＝*”代表右联接

C．Visual FoxPro同样支持超联接运算符“*＝”和“＝*”

D．利用全联接，即使两个表中的记录不满足联接条件，也会在目标表或查询结果中出现，只是不满足条件的记录对应部分为NULL

答案

参考答案：C

解析：[命题目的] 本题考查了考生对SQL查询功能的掌握情况。
[解题要点] SQL的超联接运算符中“*＝”代表左联接，“＝*”代表右联接。但在Visual FoxPro中，不支持超联接运算符“*＝”和“＝*”，它有专门的联接运算语法格式，分别用LEFT JOIN 和 RIGHT JOIN表示。
[错解分析] Visual FoxPro支持左联接和右联接运算查询，但不能使用“＝*”和“*＝”运算符查询，只能用Visual FoxPro中专用的命令短语才可以。
[考点链接] SQL超联接查询。

单项选择题共用题干题

28岁，女性，2年前剖宫产一男孩。平素月经规律，经量不多，无痛经。3个月前因使用工具避孕失败行人工流产术。术后恢复良好。要求上环就诊。

放置IUD后6个月，症状仍不见好转，拟取出IUD，改用皮下埋植避孕法，为确保安全有效，下列哪项情况存在则不予手术（）

A.有糖尿病家族史

B.血压130／90mmHg

C.高血脂

D.宫颈中度糜烂

E.偶尔吸烟

完形填空

Don’t Wait Until Flowers Fade
Each spring brings a new blossom of wildflowers in the ditches (路沟) along the highway I travel daily to work.
There is one       blue flower that has always       my eye. I’ve noticed that it blooms only in the morning hours, and the afternoon sun is too warm       it. Every day for approximately two weeks, I see those beautiful      .
This spring, I started a wildflower garden in our yard. I can look out of the       window while doing the dishes and see the flowers. I’ve often thought that those lovely blue flowers from the ditch would look       in that bed alongside       wildflowers.
Everyday I drove       the flowers thinking, “I’ll stop on my way home and dig them.” “Gee, I don’t want to get my good clothes       ...” Whatever the reason, I never stopped to dig them. My husband       gave me a folding shovel(铁锹) one year to be used for that      purpose.
One day on my way home from work, I was       to see that the highway department had moved the ditches and the pretty blue flowers were gone. I thought to myself, “Way to go, you       too long. You       it when you first saw them blooming this spring.”
A week ago we were shocked and saddened to learn that my oldest sister-in-law has a terminal brain tumor(脑瘤晚期). She is 20 years older than my husband and      , because of age and distance, we haven’t been as      as we all would have liked.
I couldn’t help but see the       between the pretty blue flowers and the     between my husband’s sister and us. I do believe that God has given us some time left to plant some valuable       that will bloom every year for us.
And yes, if I see the blue flowers again, you can bet I'll stop and       them to my wildflower garden

B．interesting

A．would have done

B．need have done

C．should have done

D．muse have done

A．unconsciously

B．fortunately

C．unfortunately

D．consciously

D．significance

B．relationship