What is a View?
A View is like a saved query. Instead of writing the same long query again and again, you save it as a View and use it like a table.
Simple analogy: Like a contact shortcut on your phone - instead of typing the full number every time, you just click the contact name.
Why Use Views?
Problem: You keep writing this long query:
SELECT name, email FROM users WHERE is_active = TRUE AND age >= 18;Solution: Save it as a View once, use it forever:
CREATE VIEW active_adults AS
SELECT name, email FROM users WHERE is_active = TRUE AND age >= 18;Now just use:
SELECT * FROM active_adults;Much easier!
How to Create a View
Example 1: Active Students
CREATE VIEW active_students AS
SELECT student_id, name, grade
FROM students
WHERE is_active = TRUE;Now you can query it like a table:
SELECT * FROM active_students;Example 2: Product Summary
CREATE VIEW product_summary AS
SELECT
product_name,
price,
stock,
price * stock AS inventory_value
FROM products
WHERE stock > 0;Use it:
SELECT * FROM product_summary WHERE price > 100;Example 3: Customer Orders
CREATE VIEW customer_orders AS
SELECT
c.name,
o.order_id,
o.total,
o.order_date
FROM customers c
JOIN orders o ON c.customer_id = o.customer_id;Real-Life Benefits
Without View (write every time):
SELECT customers.name, orders.total
FROM customers
JOIN orders ON customers.id = orders.customer_id
WHERE orders.status = 'completed';With View (write once, use many times):
CREATE VIEW completed_orders AS
SELECT customers.name, orders.total
FROM customers
JOIN orders ON customers.id = orders.customer_id
WHERE orders.status = 'completed';
-- Now just use:
SELECT * FROM completed_orders;Summary
View = Saved query
- Write complex query once
- Save it as a View
- Use it like a table
- Makes life easier