SQL Views

A view is a virtual table based on the result of a query. It does not store data itself, but displays data from underlying tables.

1️⃣ Creating a View

CREATE VIEW employee_salaries AS
SELECT name, dept_id, salary
FROM employees
WHERE salary > 50000;

-- Query like a table
SELECT * FROM employee_salaries;

2️⃣ Updating a View

CREATE OR REPLACE VIEW employee_salaries AS
SELECT name, dept_id, salary
FROM employees
WHERE salary > 60000;

3️⃣ Dropping a View

DROP VIEW employee_salaries;

4️⃣ Advantages of Views

• Simplifies queries (hide complexity).
• Security — expose only required columns/rows.
• Reusability — consistent business logic in one place.

5️⃣ Limitations

• Not all views are updatable (depends on DB & definition).
• Complex views can be slower.