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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);
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更多 “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);” 相关考题
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
Which syntax turns an existing constraint on? ()
A. ALTER TABLE table_name ENABLE constraint_name;B. ALTER TABLE table_name STATUS = ENABLE CONSTRAINT constraint _ name;C. ALTER TABLE table_name ENABLE CONSTRAINT constraint _ name;D. ALTER TABLE table_name TURN ON CONSTRAINT constraint _ name;
考题
为表TEST中ID列添加主键约束的语法是（）A、ALTER TABLE TEST CHANGE（ ID INT PRIMARY KEY）B、ALTER TABLE TEST ADD（ ID INT PRIMARY KEY）C、ALTER TABLE TEST MODIFY（ ID INT PRIMARY KEY）D、ALTER TABLE TEST ADD CONSTRAINT PK PRIMARY KEY （ID）
考题
您在公司的数据库中成功创建了名为SALARY的表。您现在要通过向引用EMPLOYEES表的匹配列的SALARY表添加FOREIGNKEY约束条件来建立EMPLOYEES表与SALARY表之间的父/子关系。尚未向SALARY表添加任何数据。应执行以下哪条语句（）A、ALTER TABLE salary ADD CONSTRAINT fk_employee_id_01 FOREIGN KEY（employee_id）REFERENCES employees（employee_id）B、ALTER TABLE salary ADD CONSTRAINT fk_employee_id_ FOREIGN KEY BETWEEN salary（employee_id）AND employees（employee_id）C、ALTER TABLE salary FOREIGN KEY CONSTRAINT fk_employee_id_REFERENCES employees（employee_id）D、ALTER TABLE salary ADD CONSTRAINT fk_employee_id_FOREIGN KEY salary（employee_id）=employees（employee_id）
考题
要向雇员表中的部门标识列添加FOREIGNKEY约束条件以引用部门表中的标识列，应该使用哪个语句（）A、ALTER TABLE雇员MODIFY COLUMN dept_id_fk FOREIGN KEY（部门标识）REFERENCES部门（部门标识）B、ALTER TABLE雇员ADD CONSTRAINT dept_id_fk FOREIGNKEY（部门标识）REFERENCES部门（部门标识）C、ALTER TABLE雇员ADD FOREIGN KEY CONSTRAINT dept_id_fk ON（部门标识）REFERENCES部门（部门标识）D、ALTER TABLE雇员ADD FOREIGN KEY 部门（部门标识）REFERENCES（部门标识）
考题
删除PRIMARYKEY约束条件及其所有依赖约束条件的语法是什么（）A、ALTER TABLE table_name DROP CONSTRAINT constraint_name CASCADEB、ALTER TABLE table_name DROP CONSTRAINT FOREIGN KEY CASCADEC、DROP CONSTRAINT table_name（constraint_name）D、ALTER TABLE table_name DROP CONSTRAINT constraint_name
考题
Which syntax turns an existing constraint on?（）A、ALTER TABLE table_name ENABLE constraint_name;B、ALTER TABLE table_name STATUS = ENABLE CONSTRAINT constraint_name;C、ALTER TABLE table_name ENABLE CONSTRAINT constraint_name;D、ALTER TABLE table_name STATUS ENABLE CONSTRAINT constraint_name;E、ALTER TABLE table_name TURN ON CONSTRAINT constraint_name;
考题
Which syntax turns an existing constraint on?（）A、ALTER TABLE table_name ENABLE constraint_name;B、ALTER TABLE table_name STATUS = ENABLE CONSTRAINT constraint _ name;C、ALTER TABLE table_name ENABLE CONSTRAINT constraint _ name;D、ALTER TABLE table_name TURN ON CONSTRAINT constraint _ name;
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 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));
考题
Which SQL statement defines the FOREIGN KEY constraint on the DEPTNO column of the EMP table?（）A、CREATE TABLE EMP (empno NUMBER(4), ename VARCNAR2(35), deptno NUMBER(7,2) NOT NULL CONSTRAINT emp_deptno_fk FOREIGN KEY deptno REFERENCES dept deptno);B、CREATE TABLE EMP (empno NUMBER(4), ename VARCNAR2(35), deptno NUMBER(7,2) CONSTRAINT emp_deptno_fk REFERENCES dept (deptno));C、CREATE TABLE EMP (empno NUMBER(4) ename VARCHAR2(35), deptno NUMBER(7,2) NOT NULL, CONSTRAINT emp_deptno_fk REFERENCES dept (deptno) FOREIGN KEY (deptno));D、CREATE TABLE EMP (empno NUMBER(4), ename VARCNAR2(35), deptno NUMBER(7,2) FOREIGN KEY CONSTRAINT emp deptno fk REFERENCES dept (deptno));
考题
Which statement adds a constraint that ensures the CUSTOMER_NAME column of the CUSTOMERS table holds a value?（）A、ALTER TABLE customers ADD CONSTRAINT cust_name_nn CHECK customer_name IS NOT NULL;B、ALTER TABLE customers MODIFY CONSTRAINT cust_name_nn CHECK customer_name IS NOT NULL;C、ALTER TABLE customers MODIFY customer_name CONSTRAINT cust_name_nn NOT NULL;D、ALTER TABLE customers MODIFY customer_name CONSTRAINT cust_name_nn IS NOT NULL;E、ALTER TABLE customers MODIFY name CONSTRAINT cust_name_nn NOT NULL;F、ALTER TABLE customers ADD CONSTRAINT cust_name_nn CHECK customer_name NOT NULL;
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 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 MODIFY CONSTRAINT stud _ id _pk PRIMARY KEY (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
Which SQL statement defines a FOREIGN KEY constraint on the DEPTNO column of the EMP table?（）A、CREATE TABLE EMP (empno NUMBER(4), ename VARCHAR2(35), deptno NUMBER(7,2) NOT NULL, CONSTRAINT emp_deptno_fk FOREIGN KEY deptno REFERENCES dept deptno);B、CREATE TABLE EMP (empno NUMBER(4), ename VARCHAR2(35), deptno NUMBER(7,2) CONSTRAINT emp_deptno_fk REFERENCES dept (deptno));C、CREATE TABLE EMP (empno NUMBER(4), ename VARCHAR2(35), deptno NUMBER(7,2) NOT NULL, CONSTRAINT emp_deptno_fk REFERENCES dept (deptno) FOREIGN KEY (deptno));D、CREATE TABLE EMP (empno NUMBER(4), ename VARCHAR2(35), deptno NUMBER(7,2) FOREIGN KEY CONSTRAINT emp_deptno_fk REFERENCES dept (deptno));
考题
The STUDENT_GRADES table has these columns: STUDENT_ID NUMBER(12) SEMESTER_END DATE GPA NUMBER(4,3) The registrar requested a report listing the students' grade point averages (GPA) sorted from highest grade point average to lowest. Which statement produces a report that displays the student ID and GPA in the sorted order requested by the registrar?（）A、SELECT student_id, gpa FROM student_grades ORDER BY gpa ASC;B、SELECT student_id, gpa FROM student_grades SORT ORDER BY gpa ASC;C、SELECT student_id, gpa FROM student_grades SORT ORDER BY gpa;D、SELECT student_id, gpa FROM student_grades ORDER BY gpa;E、SELECT student_id, gpa FROM student_grades SORT ORDER BY gpa DESC;F、SELECT student_id, gpa FROM student_grades ORDER BY gpa DESC;
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 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);
考题
单选题Which SQL statement defines the FOREIGN KEY constraint on the DEPTNO column of the EMP table?（）A
CREATE TABLE EMP (empno NUMBER(4), ename VARCNAR2(35), deptno NUMBER(7,2) NOT NULL CONSTRAINT emp_deptno_fk FOREIGN KEY deptno REFERENCES dept deptno);B
CREATE TABLE EMP (empno NUMBER(4), ename VARCNAR2(35), deptno NUMBER(7,2) CONSTRAINT emp_deptno_fk REFERENCES dept (deptno));C
CREATE TABLE EMP (empno NUMBER(4) ename VARCHAR2(35), deptno NUMBER(7,2) NOT NULL, CONSTRAINT emp_deptno_fk REFERENCES dept (deptno) FOREIGN KEY (deptno));D
CREATE TABLE EMP (empno NUMBER(4), ename VARCNAR2(35), deptno NUMBER(7,2) FOREIGN KEY CONSTRAINT emp deptno fk REFERENCES dept (deptno));
考题
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));
考题
单选题您在公司的数据库中成功创建了名为SALARY的表。您现在要通过向引用EMPLOYEES表的匹配列的SALARY表添加FOREIGNKEY约束条件来建立EMPLOYEES表与SALARY表之间的父/子关系。尚未向SALARY表添加任何数据。应执行以下哪条语句（）A
ALTER TABLE salary ADD CONSTRAINT fk_employee_id_01 FOREIGN KEY（employee_id）REFERENCES employees（employee_id）B
ALTER TABLE salary ADD CONSTRAINT fk_employee_id_ FOREIGN KEY BETWEEN salary（employee_id）AND employees（employee_id）C
ALTER TABLE salary FOREIGN KEY CONSTRAINT fk_employee_id_REFERENCES employees（employee_id）D
ALTER TABLE salary ADD CONSTRAINT fk_employee_id_FOREIGN KEY salary（employee_id）=employees（employee_id）
考题
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);
考题
单选题The STUDENT_GRADES table has these columns: STUDENT_ID NUMBER(12) SEMESTER_END DATE GPA NUMBER(4,3) The registrar requested a report listing the students' grade point averages (GPA) sorted from highest grade point average to lowest. Which statement produces a report that displays the student ID and GPA in the sorted order requested by the registrar? （）A
SELECT student_id, gpa FROM student_grades ORDER BY gpa ASC;B
SELECT student_id, gpa FROM student_grades SORT ORDER BY gpa ASC;C
SELECT student_id, gpa FROM student_grades SORT ORDER BY gpa;D
SELECT student_id, gpa FROM student_grades ORDER BY gpa;E
SELECT student_id, gpa FROM student_grades SORT ORDER BY gpa DESC;F
SELECT student_id, gpa FROM student_grades ORDER BY gpa DESC;
考题
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 _ 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
单选题Which SQL statement defines a FOREIGN KEY constraint on the DEPTNO column of the EMP table?（）A
CREATE TABLE EMP (empno NUMBER(4), ename VARCHAR2(35), deptno NUMBER(7,2) NOT NULL, CONSTRAINT emp_deptno_fk FOREIGN KEY deptno REFERENCES dept deptno);B
CREATE TABLE EMP (empno NUMBER(4), ename VARCHAR2(35), deptno NUMBER(7,2) CONSTRAINT emp_deptno_fk REFERENCES dept (deptno));C
CREATE TABLE EMP (empno NUMBER(4), ename VARCHAR2(35), deptno NUMBER(7,2) NOT NULL, CONSTRAINT emp_deptno_fk REFERENCES dept (deptno) FOREIGN KEY (deptno));D
CREATE TABLE EMP (empno NUMBER(4), ename VARCHAR2(35), deptno NUMBER(7,2) FOREIGN KEY CONSTRAINT emp_deptno_fk REFERENCES dept (deptno));
考题
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 MODIFY CONSTRAINT stud _ id _pk PRIMARY KEY (student _ id);
考题
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);
考题
单选题要向雇员表中的部门标识列添加FOREIGNKEY约束条件以引用部门表中的标识列，应该使用哪个语句（）A
ALTER TABLE雇员MODIFY COLUMN dept_id_fk FOREIGN KEY（部门标识）REFERENCES部门（部门标识）B
ALTER TABLE雇员ADD CONSTRAINT dept_id_fk FOREIGNKEY（部门标识）REFERENCES部门（部门标识）C
ALTER TABLE雇员ADD FOREIGN KEY CONSTRAINT dept_id_fk ON（部门标识）REFERENCES部门（部门标识）D
ALTER TABLE雇员ADD FOREIGN KEY 部门（部门标识）REFERENCES（部门标识）
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