单选题You created a view called EMP_DEPT_VU that contains three columns from the EMPLOYEES and DEPARTMENTS tables: EMPLOYEE_ID, EMPLOYEE_NAME AND DEPARTMENT_NAME. The DEPARTMENT_ID column of the EMPLOYEES table is the foreign key to the primary key DEPARTMEN

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单选题

You created a view called EMP_DEPT_VU that contains three columns from the EMPLOYEES and DEPARTMENTS tables: EMPLOYEE_ID, EMPLOYEE_NAME AND DEPARTMENT_NAME. The DEPARTMENT_ID column of the EMPLOYEES table is the foreign key to the primary key DEPARTMENT_ID column of the DEPARTMENTS table. You want to modify the view by adding a fourth column, MANAGER_ID of NUMBER data type from the EMPLOYEES tables. How can you accomplish this task?（）

ALTER VIEW emp_dept_vu (ADD manager_id NUMBER);

MODIFY VIEW emp_dept_vu (ADD manager_id NUMBER);

ALTER VIEW emp_dept_vu AS SELECT employee_id, employee_name, department_name, manager_id FROM employee e, departments d WHERE e.department_id = d.department_id;

MODIFY VIEW emp_dept_vu AS SELECT employee_id, employee_name, department_name, manager_id FROM employees e, departments d WHERE e.department_id = d.department_id;

CREATE OR REPLACE VIEW emp_dept_vu AS SELECT employee_id, employee_name, department_name, manager_id FROM employees e, departments d WHERE e.department_id = d.department_id;

You must remove the existing view first, and then run the CREATE VIEW command with a new column list to modify a view.

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第1题：

Examine the data in the EMPLOYEES and DEPARTMENTS tables:

EMPLOYEES

EMP_NAME DEPT_ID MGR_ID JOB_ID SALARY

EMPLOYEE_ID

101 Smith 20 120 SA_REP 4000

102 Martin 10 105 CLERK 2500

103 Chris 20 120 IT_ADMIN 4200

104 John 30 108 HR_CLERK 2500

105 Diana 30 108 IT_ADMIN 5000

106 Smith 40 110 AD_ASST 3000

108 Jennifer 30 110 HR_DIR 6500

110 Bob 40 EX_DIR 8000

120 Ravi 20 110 SA*DIR 6500

DEPARTMENTS

DEPARTMENT_ID DEPARTMENT_NAME

10 Admin

20 Education

30 IT

40 Human Resources

Also examine the SQL statements that create the EMPLOYEES and DEPARTMENTS tables:

CREATE TABLE departments

(department_id NUMBER PRIMARY KEY,

department _ name VARCHAR2(30));

CREATE TABLE employees

(EMPLOYEE_ID NUMBER PRIMARY KEY,

EMP_NAME VARCHAR2(20),

DEPT_ID NUMBER REFERENCES

departments(department_id),

MGR_ID NUMBER REFERENCES

employees(employee id),

MGR_ID NUMBER REFERENCES

employees(employee id),

JOB_ID VARCHAR2(15).

SALARY NUMBER);

ON the EMPLOYEES,

On the EMPLOYEES table, EMPLOYEE_ID is the primary key.

MGR_ID is the ID of managers and refers to the EMPLOYEE_ID. DEPT_ID is foreign key to DEPARTMENT_ID column of the DEPARTMENTS table. On the DEPARTMENTS table, DEPARTMENT_ID is the primary key.

Examine this DELETE statement:

DELETE

FROM departments

WHERE department id = 40;

What happens when you execute the DELETE statement?（）

参考答案：B

第2题：

Examine the structure of the EMPLOYEES and DEPARTMENTS tables: EMPLOYEESColumn name Data type Remarks EMPLOYEE_ID NUMBER NOT NULL, Primary Key EMP_NAME VARCHAR2 (30) JOB_ID VARCHAR2 (20) SALARY NUMBER MGR_ID NUMBER References EMPLOYEE_ID COLUMN DEPARTMENT ID NUMBER Foreign key to DEPARTMENT ID column of the DEPARTMENTS table DEPARTMENTSColumn name Data type Remarks DEPARTMENT_ID NUMBER NOT NULL, Primary Key DEPARTMENT_NAME VARCHAR2(30) MGR_ID NUMBER References MGR_ID column of the EMPLOYEES table Evaluate this SQL statement: SELECT employee_id, e.department_id, department_name, salary FROM employees e, departments d WHERE e. department_id = d.department_id; Which SQL statement is equivalent to the above SQL statement? （）

A、SELECT employee_id, department_id, department_name, salary FROM employees WHERE department_id IN (SELECT department_id FROM departments);
B、SELECT employee_id, department_id, department_name, salary FROM employees NATURAL JOIN departments;
C、SELECT employee_id, d.department_id, department_name, salary FROM employees e JOIN departments d ON e.department _ id = d. department_id;
D、SELECT employee_id, department_id, department_name, Salary FROM employees JOIN departments USING (e.department_id, d.department_id);

正确答案:C

第3题：

Examine the data in the EMPLOYEES table.On the EMPLOYEES table, EMPLOYEE_ID is the primary key. MGR_ID is the ID of managers and refers to the EMPLOYEE_ID. The JOB_ID column is a NOT NULL column.Evaluate this DELETE statement:Why does the DELETE statement fail when you execute it?（）

A. There is no row with dept_id 90 in the EMPLOYEES table.

B. You cannot delete the JOB_ID column because it is a NOT NULL column.

C. You cannot specify column names in the DELETE clause of the DELETE statement.

D. You cannot delete the EMPLOYEE_ID column because it is the primary key of the table.

参考答案：C

第4题：

Examine the structure of the EMPLOYEES table: EMPLOYEE_ID NUMBER NOT NULL, Primary Key EMP_NAME VARCHAR2(30) JOB_ID NUMBER/ SAL NUMBER MGR_ID NUMBER References EMPLOYEE_ID column DEPARTMENT_ID NUMBER Foreign key to DEPARTMENT_ID column of the DEPARTMENTS table You created a sequence called EMP_ID_SEQ in orderto populate sequential values for the EMPLOYEE_ID column of the EMPLOYEES table. Which two statements regarding the EMP_ID_SEQ sequence are true? （）

A、You cannot use the EMP_ID_SEQ sequence to populate the JOB_ID column.
B、The EMP_ID_SEQ sequence is invalidated when you modify the EMPLOYEE_ID column.
C、The EMP_ID_SEQ sequence is not affected by modifications to the EMPLOYEES table.
D、Any other column of NUMBER data type in your schema can use the EMP_ID_SEQ sequence.
E、The EMP_ID_SEQ sequence is dropped automatically when you drop the EMPLOYEES table.
F、The EMP_ID_SEQ sequence is dropped automatically when you drop the EMPLOYEE_ID column.

正确答案:C,D

第5题：

A、ALTER VIEW EMP_dept_vu (ADD manger_id NUMBER);
B、MODIFY VIEW EMP_dept_vu (ADD manger_id NUMBER);
C、ALTER VIEW emp_dept_vu AS SELECT employee_id, employee_name, department_name, manager_id FROM employee e, departments d WHERE e.department _ id = d.department_id;
D、MODIFY VIEW emp_dept_vu AS SELECT employee_id, employee_name, department_name, manager_id FROM employees e, departments d WHERE e.department _ id = d.department_id;
E、CREATE OR REPLACE VIEW emp_dept_vu AS SELECT employee_id, employee_name, department_name, manager_id FROM employees e, departments d WHERE e.department _ id = d.department_id;
F、You must remove the existing view first, and then run the CREATE VIEW command with a new column list to modify a view.

正确答案:E

第6题：

Click the Exhibit button and examine the data in the EMPLOYEES table.On the EMPLOYEES table, EMPLOYEE_ID is the primary key. MGR_ID is the ID of managers and refers to the EMPLOYEE_ID. The JOB_ID column is a NOT NULL column.Evaluate this DELETE statement:DELETE employee_id, salary, job_idFROM employeesWHERE dept_id = 90;Why does the DELETE statement fail when you execute it?（）

A.There is no row with dept_id 90 in the EMPLOYEES table.

B.You cannot delete the JOB_ID column because it is a NOT NULL column.

C.You cannot specify column names in the DELETE clause of the DELETE statement.

D.You cannot delete the EMPLOYEE_ID column because it is the primary key of the table.

参考答案：C

第7题：

Examine the structure if the EMPLOYEES table: Column name Data Type Remarks EMPLOYEE_ID NUMBER NOT NULL, Primary Key EMP_NAME VARCHAR2(30) JOB_ID VARCHAR2(20) NOT NULL SAL NUMBER MGR_ID NUMBER References EMPLOYEE_ID column DEPARTMENT_ID NUMBER Foreign key to DEPARTMENT_ID column of the DEPARTMENTS table You need to create a view called EMP_VU that allows the user to insert rows through the view. Which SQL statement, when used to create the EMP_VU view, allows the user to insert rows? （）

A、CREATE VIEW emp_Vu AS SELECT employee_id, emp_name, department_id FROM employees WHERE mgr_id IN (102, 120);
B、CREATE VIEW emp_Vu AS SELECT employee_id, emp_name, job_id department_id FROM employees WHERE mgr_id IN (102, 120);
C、CREATE VIEW emp_Vu AS SELECT department_id, SUM(sal) TOTALSAL FROM employees WHERE mgr_id IN (102, 120) GROUP BY department_ id;
D、CREATE VIEW emp_Vu AS SELECT employee_id, emp_name, job_id, DISTINCT department_id FROM employees;

正确答案:B

第8题：

Examine the data in the EMPLOYEES and DEPARTMENTS tables:Also examine the SQL statements that create the EMPLOYEES and DEPARTMENTS tables:On the EMPLOYEES table, EMPLOYEE_ID is the primary key.MGR_ID is the ID of managers and refers to the EMPLOYEE_ID.DEPT_ID is foreign key to DEPARTMENT_ID column of the DEPARTMENTS table.On the DEPARTMENTS table, DEPARTMENT_ID is the primary key.Examine this DELETE statement:What happens when you execute the DELETE statement?（）

A. Only the row with department ID 40 is deleted in the DEPARTMENTS table.

B. The statement fails because there are child records in the EMPLOYEES table with department ID 40.

C. The row with department ID 40 is deleted in the DEPARTMENTS table. Also the rows with employee IDs 110 and 106 are deleted from the EMPLOYEES table.

D. The row with department ID 40 is deleted in the DEPARTMENTS table. Also the rows with employee IDs 106 and 110 and the employees working under employee 110 are deleted from the EMPLOYEES table.

E. The row with department ID 40 is deleted in the DEPARTMENTS table. Also all the rows in the EMPLOYEES table are deleted.

F. The statement fails because there are no columns specifies in the DELETE clause of the DELETE statement.

参考答案：B

第9题：

A、SELECT employee_id, department_id, department_name, salary FROM employees WHERE department_id IN (SELECT department_id FROM departments);
B、SELECT employee_id, department_id, department_name, salary FROM employees NATURAL JOIN departments;
C、SELECT employee_id, d.department_id, department_name, salary FROM employees e JOIN departments d ON e.department _ id = d. department_id;
D、SELECT employee_id, department_id, department_name, Salary FROM employees JOIN departments USING (e.department_id, d.department_id);

正确答案:C

第10题：

Examine the data in the EMPLOYEES and DEPARTMENTS tables: EMPLOYEES EMP_NAME DEPT_ID MGR_ID JOB_ID SALARY EMPLOYEE_ID 101 Smith 20 120 SA_REP 4000 102 Martin 10 105 CLERK 2500 103 Chris 20 120 IT_ADMIN 4200 104 John 30 108 HR_CLERK 2500 105 Diana 30 108 IT_ADMIN 5000 106 Smith 40 110 AD_ASST 3000 108 Jennifer 30 110 HR_DIR 6500 110 Bob 40 EX_DIR 8000 120 Ravi 20 110 SA*DIR 6500 DEPARTMENTS DEPARTMENT_ID DEPARTMENT_NAME 10 Admin 20 Education 30 IT 40 Human Resources Also examine the SQL statements that create the EMPLOYEES and DEPARTMENTS tables: CREATE TABLE departments (department_id NUMBER PRIMARY KEY, department _ name VARCHAR2(30)); CREATE TABLE employees (EMPLOYEE_ID NUMBER PRIMARY KEY, EMP_NAME VARCHAR2(20), DEPT_ID NUMBER REFERENCES departments(department_id), MGR_ID NUMBER REFERENCES employees(employee id), MGR_ID NUMBER REFERENCES employees(employee id), JOB_ID VARCHAR2(15). SALARY NUMBER); ON the EMPLOYEES, On the EMPLOYEES table, EMPLOYEE_ID is the primary key. MGR_ID is the ID of managers and refers to the EMPLOYEE_ID. DEPT_ID is foreign key to DEPARTMENT_ID column of the DEPARTMENTS table. On the DEPARTMENTS table, DEPARTMENT_ID is the primary key. Examine this DELETE statement: DELETE FROM departments WHERE department id = 40; What happens when you execute the DELETE statement?（）

A、Only the row with department ID 40 is deleted in the DEPARTMENTS table.
B、The statement fails because there are child records in the EMPLOYEES table with department ID 40.
C、The row with department ID 40 is deleted in the DEPARTMENTS table. Also the rows with employee IDs 110 and 106 are deleted from the EMPLOYEES table.
D、The row with department ID 40 is deleted in the DEPARTMENTS table. Also the rows with employee IDs 106 and 110 and the employees working under employee 110 are deleted from the EMPLOYEES table.
E、The row with department ID 40 is deleted in the DEPARTMENTS table. Also all the rows in the EMPLOYEES table are deleted.
F、The statement fails because there are no columns specifies in the DELETE clause of the DELETE statement.

正确答案:B

单选题You created a view called EMP_DEPT_VU that contains three columns from the EMPLOYEES and DEPARTMENTS tables: EMPLOYEE_ID, EMPLOYEE_NAME AND DEPARTMENT_NAME. The DEPARTMENT_ID column of the EMPLOYEES table is the foreign key to the primary key DEPARTMEN

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