Database Practice of the Day (2017/8/1)
(Multiple Choice) 1. The operation that cannot be done on a view is ()?
A Update view
B Enquiry
C Define a new table on the view
D Define a new view on the view
(Multiple Choice) 2. According to the traditional data model classification, database systems can be classified into three types ().
A Large, medium and small
B Western, Chinese and compatible
C Hierarchy, webs and relationships
D Data, graphics and multimedia
(Multiple Choice) 3. In the SELECT statement of SQL language, which clause () implements the sort operation.
A WHERE
B FROM
C SELECT
D ORDER BY
(Multiple Choice) 4. DBMS provides DML to implement operations on data. A DML that can be used interactively on its own is called ().
A Host type
B Independent
C Self-contained
D Embedded
(Multiple Choice) 5. The main functions of JDBC are? 1/1
A Creating a connection to the database
B Send SQL statements to the database
C Processing data and querying results
D All of the above
(Multiple choice) 6. table toutiao_tb
title data auther type
abc 2016.2.23 bob 1
bcv 2016.3.3 http 1
cvt 2016.3.3 http 1
bcvvcm 2016.3.5 js 2
nmhh 2016.2.3 html 2
hhj 2016.3.3 java 3
rrr 2016.3.2 cc 1
Query for records whose title contains cv and whose type is 1
A select * from toutiao_tb where title = 'cv' and type='1'
B select * from toutiao_tb where title like '%cv%' andtype=1
C select * from toutiao_tb where title like '*cv' andtype=1
D select * from toutiao_tb where title ='*cv*' and type='1‘
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Previous answer.
(Multiple Choice) 1. There is a method run() inside the class Car. If you use Car.run() directly, the keyword that must be used before the method run is? ( )
A class
B final
C public
D static
The correct answer is:D
Ans: The method modified by static can be called directly by using the class name and method name...
(Multiple Choice) 2. When declaring an interface using interface, only () modifier can be used to modify the interface
A private
B protected
C private protected
D public
The correct answer is: D
Ans: The interface must be inherited, so it has to be public
(Multiple Choice) 3. The character code set used by the java language is
A ASCII
B BCD
C DCB
D Unicode
The correct answer is: D
Ans: The Java language uses the Unicode character set, ASCII is the most widely used character encoding internationally
(Indefinite choice) 4、Which of the following options is a legal method definition in interface? ()
A public void main(String [] args);
B private int getSum();
C boolean setFlag(Boolean [] test);
D public float get(int x);
The correct answer is: ACD
Ans: The entry point of a java program must be of static type and methods of static type are not allowed in the interface. A does not have the static modifier and can be used as a normal method. And the methods in the interface must be public. Consider that excuses are meant to be implemented by others and are equivalent to standards, and it is unreasonable for standards not to allow others to use them, so the methods in the interface must be public. In item C, the methods in the interface are public by default. D is the normal method. So the answer is: ACD
(Multiple Choice) 5. Java programs that use the assignment operator for object assignment can get two identical objects.
A Correct
B Wrong
The correct answer is:A
Ans: When an object is assigned, for example, A=B, it just points the address of the A object to the address of the B object, so there is actually only one object
(Indefinite Choice) 6. cannot be used to modify interface are ()1/1
A private
B public
C protected
D static
The correct answer is: : ACD
Analysis.
A,C,D can't be used to modify interface.
In terms of access, you can use the public,default modifier, but not private, because the interface itself is meant to be used by other classes or interfaces, and using private would be pointless.
protected is also not allowed, ptotected access is the package object as well as outside the package inheritance of the class outside the package object, in fact, and public meaning will be the same, there is no need to choose protected.
The static is used to modify variables or methods, not classes. (In an interface, static can only modify variables, not methods)
(final also does not modify interfaces)
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