考题
You need to design a student registration database that contains several tables storing academic information.The STUDENTS table stores information about a student. The STUDENT_GRADES table storesinformation about the student‘s grades. Both of the tables have a column named STUDENT_ID. The STUDENT_ID column in the STUDENTS table is a primary key.You need to create a foreign key on the STUDENT_ID column of the STUDENT_GRADES table thatpoints to the STUDENT_ID column of the STUDENTS table. Which statement creates the foreign key?()A. CREATE TABLE student_grades (student_id NUMBER(12),semester_end DATE, gpa NUMBER(4,3), CONSTRAINT student_id_fk REFERENCES (student_id) FOREIGN KEY student (student_id));B. CREATE TABLE student_grades(student_id NUMBER(12),semester_end DATE, gpa NUMBER(4,3), student_id_fk FOREIGN KEY (student_id) REFERENCES students (student_id));C. CREATE TABLE student_grades(student_id NUMBER(12),semester_end DATE, gpa NUMBER(4,3), CONSTRAINT FOREIGN KEY (student_id) REFERENCES student (student_id));D. CREATE TABLE student_grades(student_id NUMBER(12),semester_end DATE, gpa NUMBER(4,3), CONSTRAINT student_id_fk FOREIGN KEY (student_id) REFERENCES students (student_id));
考题
You need to modify the STUDENTS table to add a primary key on the STUDENT_ID column. The table is currently empty. Which statement accomplishes this task?()
A. ALTER TABLE students ADD PRIMARY KEY _ id;B. ALTER TABLE students ADD CONSTRAINT PRIMARY KEY (student_id);C. ALTER TABLE students ADD CONSTRAINT stud_id_pk PRIMARY KEY student_id;D. ALTER TABLE students ADD CONSTRAINT stud_id_pk PRIMARY KEY (student_id);E. ALTER TABLE students MODIFY CONSTRAINT stud_id_pk PRIMARY KEY (student_id);
考题
Which statement explicitly names a constraint? ()
A. ALTER TABLE student_grades ADD FOREIGN KEY (student_id) REFERENCES students (student_id);B. ALTER TABLE student_grades ADD CONSTRAINT NAME = student_id_fk FOREIGN KEY (student_id) REFERENCES students (student_id);C. ALTER TABLE student_grades ADD CONSTRAINT student_id_fk FOREIGN KEY (student_id) REFERENCES students (student_id);D. ALTER TABLE student grades ADD NAMED CONSTRAINT student_id_fk FOREIGN KEY (student_id) REFERENCES students (student_id);E. ALTER TABLE student grades ADD NAME student_id_fk FOREIGN KEY (student_id) REFERENCES students (student_id);
考题
The STUDENT_GRADES table has these columns:The register has requested a report listing the students‘ grade point averages (GPA), sorted from highest grade point average to lowest within each semester, starting from the earliest date. Which statement accomplishes this?()A. SELECT student_id, semester_end, gpa FROM student_grades ORDER BY semester_end DESC, gpa DESC;B. SELECT student_id, semester_end, gpa FROM student_grades ORDER BY semester_end ASC, gpa ASC;C. SELECT student_id, semester_end, gpa FROM student_grades ORDER BY semester_end, gpa DESC;D. SELECT student_id, semester_end, gpa FROM student_grades ORDER BY gpa DESC, semester_end DESC;E. SELECT student_id, semester_end, gpa FROM student_grades ORDER BY gpa DESC, semester_end ASC;
考题
有以下程序:includeusing namespace std;class MyClass{public:MyClass(int n){numbe
有以下程序: #include<iostream> using namespace std; class MyClass { public: MyClass(int n){number=n;} //拷贝构造函数 MyClass(MyClassother) {number=other.number;} ~MyClass() {} private: int number; }; MyClass fun(MyClass p)A.5B.4C.3D.2
考题
阅读以下Java代码,填充(1)~(5)的空缺,将解答填入答题纸的对应栏内。 【说明】进行两个整数之间的比较,由考生通过输入窗口分别输入两个整数,程序比较出结果。例如:先后输入的两个数分别为25和36。 比较结果显示: 25!=36 25<36 25<=36 【Java代码】 import javax.swing.JOptionPane; public class Java3 { public static void main(String args[]) { String (1) //用户输入第1个字符串 secondNuimber, //用户输入第2个字符串 result; //包含输出结果的字符串 int number1, //比较的第1个数 number2; //比较的第2个数 //读用户输入的第1个字符串 firstNumber= JOptionPane(2)("Enter first integer:"); //读用户输入的第2个字符串 secondNumber= JOpttionPane.showlnputDialog("Enter second integer:"); //将字符串类型转换成整数类型 number1=Integer.(3)(firstNumber); number2=Integer.parselnt(secondNumber); result=""; if((4)) result=number1+"=="+number2; if(number1!=number2) result=number1+"!=”"+number2; if(number1<number2) result=result+"\n"+number1+"<"+number2; if(numbe1>number2) result=result+"\n"+number1+">"+number2; if(number1<=number2) result=result+"\n"+number1+"<="+number2; if(number1>=number2) result=result+"\n"+number1+">="+number2; //显示结果 JOptionPane.(5)( null,result,"Comparison Results", JOptionPane.INFORMATION_MESSAGE.; //程序正常退出 System.exit(0); }}
考题
下列代码最终结果不是NAN的是()。A.Number(“12你好”);B.parseInt(“12你好”);C.parseFloat(“你好12”);D.Number(“你好12”);
考题
下列代码最终结果不是NAN的是()。A.parseFloat(“你好12”);B.Number(“你好12”);C.Number(“12你好”);D.parseInt(“12你好”);
考题
下列代码最终结果不是NAN的是()。A.parseFloat(“你好12”);B.Number(“12你好”);C.Number(“你好12”);D.parseInt(“12你好”);
考题
16、MySQL数据库中,通常将用户写入对应的权限表来控制访问权限的,以下属于用户权限得选项()。A.UserB.dbC.table_privD.columns_priv