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

ALTER VIEW EMP_dept_vu (ADD manger_id NUMBER);

MODIFY VIEW EMP_dept_vu (ADD manger_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.