Few students failed in the exam at the end of last term,（） ?..

第1题

[单选题] 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);

点击查看答案

第2题

[单选题] 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);

点击查看答案

第3题

[] Which statement explicitly names a constraint?（）

A、A. ALTER TABLE student_grades ADD FOREIGN KEY (student_id) REFERENCES students (student_id); B、B. ALTER TABLE student_grades ADD CONSTRAINT NAME = student_id_fk FOREIGN KEY (student_id) REFERENCES students (student_id); C、C. ALTER TABLE student_grades ADD CONSTRAINT student_id_fk FOREIGN KEY (student_id) REFERENCES students (student_id); D、D. ALTER TABLE student grades ADD NAMED CONSTRAINT student_id_fk FOREIGN KEY (student_id) REFERENCES students (student_id); E、E. ALTER TABLE student grades ADD NAME student_id_fk FOREIGN KEY (student_id) REFERENCES students (student_id);

点击查看答案

第4题

[单选题] 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 stores information 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 that points 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));

点击查看答案

第5题

[单选题] 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 stores information 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 that points 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));

点击查看答案

第6题

[多选题] 对于如下代码，描述正确的是哪项？（） class Student{ public static void main（String[] args）{ Student student=new Student（）； } }

A、new Student（）创建了Student对象的一个实例 B、Student student声明了对象Student的一个引用 C、class Student声明了一个类 D、new Student（）创建了一个类 E、Student student 声明了一个类

点击查看答案

第7题

[] 对于如下代码，描述正确的是哪项？（） class Student{ public static void main（String[] args）{ Student student = new Student（）； } } 对于如下代码，描述正确的是哪项？（） class Student{ public static void main（String[] args）{ Student student = new Student（）； } }

A、A.Student student 声明了一个类 B、B.new Student（）创建了Student 对象的一个实例 C、C.Student student 声明了对象Student 的一个引用 D、D.class Student 声明了一个类

点击查看答案

第8题

[单选题] 下列对$student使用正确的是（）。

A、$student->$getName（）； B、$student->name； C、$student->$name； D、$student.getName（）；

点击查看答案

第9题

[单选题] 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 student_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);

点击查看答案

Few students failed in the exam at the end of last term,（） ?

请使用微信扫码支付