Examine the structure of 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 users to insert rows through the view.
Which SQL statement, when used to create the EMP_VU view, allows the users 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 employee_id, emp_name, job_id,
DISTINCT department_id
FROM employees;
D.
CREATE VIEW emp_vu AS
SELECT department_id, SUM(sal) TOTALSAL
FROM employees
WHERE mgr_id IN (102, 120)
GROUP BY department_id;
Explanation:
This statement will create view that can be used to change tables in underlying table through
simple views. It includes primary key, NOT NULL column and foreign key to avoid constraint
restrictions.