Which optional clause is used to reject inserts and updates that do not satisfy the WHERE clause of a view query?
AnswerA
ExplanationWhen a VIEW is created in SQL, users may insert or update data through that view. However, if a row is inserted or updated in such a way that it violates the condition of the VIEW's WHERE clause, it can lead to inconsistencies.
To prevent such unwanted modifications, SQL provides the WITH CHECK OPTION clause.
How WITH CHECK OPTION Works:
Ensures that any new data (INSERT/UPDATE) still fits within the defined constraints of the VIEW.
If a user tries to insert or update a row that would not appear in the VIEW, the operation is rejected.
Example:
sql
CREATE VIEW HighSalaryEmployees AS
SELECT * FROM Employees WHERE Salary > 50000
WITH CHECK OPTION;
Now, if someone attempts:
sql
INSERT INTO HighSalaryEmployees (ID, Name, Salary)
VALUES (101, 'Alice', 30000);
This fails because 30000 does not satisfy Salary > 50000.
Why Other Options Are Incorrect:
Option B (Incorrect): JOIN VIEWS is not a valid SQL clause.
Option C (Incorrect): MATERIALIZED VIEW refers to stored views in some databases, but it does not reject incorrect inserts/updates.
Option D (Incorrect): BASE TABLE refers to the original table from which a VIEW is created.
Thus, the correct answer is WITH CHECK OPTION, which ensures that only valid data modifications occur.