SQL笔试题（单选20道）

一、单选题

1、SQL 指的是？

A、Strong Question Language

B、Structured Question Language

C、Structured Query Language

答案：C

2、哪个 SQL 语句用于从数据库中提取数据？

A、EXTRACT

B、SELECT

C、OPEN

D、GETB

答案：B

3.哪条 SQL 语句用于更新数据库中的数据？

A、MODIFY

B、SAVE AS

C、UPDATE

D、SAVE

答案：C

4、哪条 SQL 语句用于删除数据库中的数据？

A、COLLAPSE

B、DELETE

C、REMOVE

答案：B

5、哪条 SQL 语句用于在数据库中插入新的数据？

A、INSERT NEW

B、ADD RECORD

C、ADD NEW

D、INSERT INTO

答案：D

6、通过 SQL，您如何从 "Persons" 表中选取 "FirstName" 列？

A、SELECT Persons.FirstName

B、SELECT FirstName FROM Persons

C、EXTRACT FirstName FROM Persons

答案：B

7、通过 SQL，您如何从 "Persons" 表中选取所有的列？

A、SELECT [all] FROM Persons

B、SELECT Persons

C、SELECT * FROM Persons

D、SELECT *.Persons

答案：C

8、通过 SQL，您如何从 "Persons" 表中选取 "FirstName" 列的值等于"Peter" 的所有记录？

A、SELECT [all] FROM Persons WHERE FirstName='Peter'

B、SELECT * FROM Persons WHERE FirstName LIKE 'Peter'

C、SELECT [all] FROM Persons WHERE FirstName LIKE 'Peter'

D、SELECT * FROM Persons WHERE FirstName='Peter'

答案：D

9、通过 SQL，您如何从 "Persons" 表中选取 "FirstName" 列的值以 "a" 开头的所有记录？

A、SELECT * FROM Persons WHERE FirstName LIKE 'a%'

B、SELECT * FROM Persons WHERE FirstName='a'

C、SELECT * FROM Persons WHERE FirstName LIKE '%a'

D、SELECT * FROM Persons WHERE FirstName='%a%'

答案：A

10、请判断下列说法是否正确：当所列出的某个条件为 true 时，OR 运算符会显示记录。当列出的所有条件为 true 时，AND 运算符会显示记录。

A、正确

B、错误

答案：A

11、通过 SQL，您如何在表 Persons 中选择 FirstName 等于 Thomas 而 LastName 等于 Carter 的所有记录？

A、SELECT * FROM Persons WHERE FirstName LIKE 'Thomas' AND LastName LIKE 'Carter'

B、SELECT FirstName='Thomas', LastName='Carter' FROM Persons

C、SELECT * FROM Persons WHERE FirstName='Thomas' AND LastName='Carter'

答案：C

12、通过 SQL，您如何按字母顺序选取 Persons 表中 LastName 介于 Adams 和 Carter 的所有记录？

A、SELECT * FROM Persons WHERE LastName BETWEEN 'Adams' AND 'Carter'

B、SELECT * FROM Persons WHERE LastName>'Adams' AND LastName<'Carter'

C、SELECT LastName>'Adams' AND LastName<'Carter' FROM Persons

答案：A

13、哪条 SQL 语句可返回唯一不同的值？

A、SELECT DIFFERENT

B、SELECT DISTINCT

C、SELECT UNIQUE

答案：B

14、哪个 SQL 关键词用于对结果集进行排序？

A、ORDER

B、SORT BY

C、SORT

D、ORDER BY

答案：D

15、通过 SQL，您如何根据 "FirstName" 列降序地从 "Persons" 表返回所有记录？

A、SELECT * FROM Persons SORT 'FirstName' DESC

B、SELECT * FROM Persons ORDER BY FirstName DESC

C、SELECT * FROM Persons ORDER FirstName DESC

D、SELECT * FROM Persons SORT BY 'FirstName' DESC

答案：B

16、通过 SQL，您如何向 "Persons" 表插入新的记录？

A、INSERT ('Jimmy', 'Jackson') INTO Persons

B、INSERT VALUES ('Jimmy', 'Jackson') INTO Persons

C、INSERT INTO Persons VALUES ('Jimmy', 'Jackson')

答案：D

17、通过 SQL，您如何向 "Persons" 表中的 "LastName" 列插入 "Wilson" ？

A、INSERT INTO Persons (LastName) VALUES ('Wilson')

B、INSERT ('Wilson') INTO Persons (LastName)

C、INSERT INTO Persons ('Wilson') INTO LastName

答案：A

18、您如何把 "Persons" 表中 "LastName" 列的 "Gates" 改为 "Wilson" ？

A、MODIFY Persons SET LastName='Wilson' WHERE LastName='Gates'

B、UPDATE Persons SET LastName='Wilson' WHERE LastName='Gates'

C、UPDATE Persons SET LastName='Wilson' INTO LastName='Gates'

D、MODIFY Persons SET LastName='Wilson' INTO LastName='Gates'

答案：B

19、通过 SQL，您如何在 "Persons" 表中删除 "FirstName" 等于 "Fred" 的纪录？

A、DELETE FROM Persons WHERE FirstName = 'Fred'

B、DELETE FirstName='Fred' FROM Persons

C、DELETE ROW FirstName='Fred' FROM Persons

答案：A

20、通过 SQL，您如何返回 "Persons" 表中记录的数目？

A、SELECT COLUMNS() FROM Persons

B、SELECT COLUMNS(*) FROM Persons

C、SELECT COUNT() FROM Persons

D、SELECT COUNT(*) FROM Persons

答案：D

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