1. Create a view called EMPLOYEES_VU based on the employee numbers, employee names, and
   department numbers from the EMPLOYEES table. Change the heading for the employee name to
   EMPLOYEE.

	CREATE OR REPLACE VIEW employees_vu AS
	SELECT employee_id, last_name employee, department_id
	FROM employees;
2. Display the contents of the EMPLOYEES_VU view.
	
	SELECT *
	FROM employees_vu;

3. Select the view name and text from the USER_VIEWS data dictionary view.
   Note: Another view already exists. The EMP_DETAILS_VIEW was created as part of your
   schema.
   Note: To see more contents of a LONG column, use the iSQL*Plus command SET LONG n,
   where n is the value of the number of characters of the LONG column that you want to see.

	SET LONG 600
	SELECT view_name, text
	FROM user_views;

4. Using your EMPLOYEES_VU view, enter a query to display all employee names and department
   numbers.

	SELECT employee, department_id
	FROM employees_vu;

5. Create a view named DEPT50 that contains the employee numbers, employee last names, and
   department numbers for all employees in department 50. Label the view columns
   EMPNO, EMPLOYEE, and DEPTNO. Do not allow an employee to be reassigned to another
   department through the view.

	CREATE VIEW dept50 AS
	SELECT employee_id empno, last_name employee,
	department_id deptno
	FROM employees
	WHERE department_id = 50
	WITH CHECK OPTION CONSTRAINT emp_dept_50;

6. Display the structure and contents of the DEPT50 view.

	DESCRIBE dept50

	SELECT *
	FROM dept50;

7. Attempt to reassign Matos to department 80.

	UPDATE dept50
	SET deptno = 80
	WHERE employee = ’Matos’;


8. Create a view called SALARY_VU based on the employee last names, department names, salaries,
   and salary grades for all employees. Use the EMPLOYEES, DEPARTMENTS, and JOB_GRADES
   tables. Label the columns Employee, Department, Salary, and Grade, respectively.

	CREATE OR REPLACE VIEW salary_vu
	AS
	SELECT e.last_name "Employee",
	d.department_name "Department",
	e.salary "Salary",
	j.grade_level "Grades"
	FROM employees e,
	departments d,
	job_grades j
	WHERE e.department_id = d.department_id
	AND e.salary BETWEEN j.lowest_sal and j.highest_sal;