举一反三
- 查询图书价格在30到50之间的图书名、作者和出版社,其中的查询条件表达式为（） A: where price>;=30 AND price<;=50 B: where price>;=30 OR price<;=50 C: where priceBETWEEN 30 AND 50 D: where priceBETWEEN50 AND 30
- 分析以下SQL 命令: SELECT price FROM inventory WHERE price BETWEEN 1 AND 50 AND (price IN(55, 30, 95); 命令执行后的输出结果是：（） A: 55 B: 30 C: 95 D: NULL
- 阅读下面T-SQL语句，对变量赋值时存在错误的是（ ）（其中money为钱币数据类型，为其变量赋值可用或者不用$等货币符号）。 A: declare @id int ,@price money Set @id =100 Set @price=$2.21 B: declare @id int ,@price money Select @id=100,@price=2.21 C: declare @id int ,@price money set @id=100,@price=2.21 D: declare @id int ,@price money Select @id=100Select @price=$2.21
- 【单选题】显示图书信息表中不同书架图书的平均价格大于50元的书架号和平均价格。能得到正确结果的SELECT语句是 A: select casename,AVG(price) <br> from bookinfo group by casename where AVG(price)>50 B: select casename,AVG(price)>50 from bookinfo group by casename C: select casename,AVG(price) <br> from bookinfo<br> having AVG(price)>50 group by casename D: select casename,AVG(price) <br> from bookinfo group by casename<br> having AVG(price)>50
- Suppose the price index was 100 in 2014, 109 in 2015, and the inflation rate was lower between 2015 and 2016 than it was between 2014 and 2015. This means that
内容
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下列选项中与“WHERE (id,price)=(3,1999)”功能相同的是( ) A: WHERE id=3 || price=1999 B: WHERE id=3 && price=1999 C: WHERE (id,price)<>(3,1999) D: 以上选项都不正确
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设变量已正确定义,选项()与以下程序段不等价。switch(choice){case1:price=3.0;case2:price=2.5;default:price=0.0;}A.price=0.0;B.switch(choice){default:price=0.0;case2:price=2.5;case1:price=3.0;}C.price=0.0;switch(choice){case1:price=3.0;case2:price=2.5;}D.if(choice==1){price=3.0;price=2.5;price=0.0;}elseif(choice==2){price=2.5;price=0.0;}else{price=0.0;}
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Could you please ________ 50 metric tons of peanuts A: quote us your best price for B: quote for us your best price for C: quote us for your best price for D: quote us at your best price
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分析以下SQL 命令执行后的输出结果是( )。[br][/br]SELECT price[br][/br]FROM inventory[br][/br]WHERE price BETWEEN 1 AND 50[br][/br]AND (price IN(55, 30, 95); A: 55 B: 95 C: 30 D: NULL
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下列多条件查询使用正确的有（） A: B: and查询db.collection.find({ $and : [ { "age" : {$gt : 10 }} , { "gender" : "man" } ]}) C: ＃or查询db.collection.find({ $or : [ {"age" : {$gt : 10 }}, { "gender" : "man"} ]}) D: E: and查询和or查询db.inventory.find( { $and : [ { $or : [ { price : 0.99 }, { price : 1.99 } ] }, { $or : [ { sale : true }, { qty : { $lt : 20 } } ] } ]} ) F: G: and查询和or查询db.inventory.find( { $or: [ { $and : [ { price : 0.99 }, { price : 1.99 } ] }, { $: [ { sale : true }, { qty : { $lt : 20 } } ] } ]} )