Views are virtual tables based on queries. They don't store data themselves but provide a simplified or secured window into your actual tables.

Creating a Simple View

CREATE VIEW active_customers AS
SELECT customer_id, name, email, registration_date
FROM customers
WHERE status = 'active' AND deleted_at IS NULL;

Using Views Like Tables

-- Query the view just like a table
SELECT * FROM active_customers
WHERE registration_date >= '2024-01-01';

Complex View with Joins

CREATE VIEW customer_order_summary AS
SELECT
    c.customer_id,
    c.name,
    c.email,
    COUNT(o.order_id) as total_orders,
    SUM(o.total) as lifetime_value,
    MAX(o.order_date) as last_order_date
FROM customers c
LEFT JOIN orders o ON c.customer_id = o.customer_id
GROUP BY c.customer_id, c.name, c.email;

Views vs Tables

Views	Tables
Virtual (no data storage)	Physical data storage
Always show current data	Store historical snapshots
Simplify complex queries	Direct data manipulation
Security layer (hide columns)	Full data access required

When to Use Views

• Hide sensitive columns (e.g., salaries, passwords)
• Simplify complex joins for end users
• Create consistent calculated fields
• Maintain backward compatibility when table structure changes