= Customer order history

=== Description
This view provides a complete history of orders made by customers, including order details and the products included in each order.

The view is intended for:

- displaying customer order history
- tracking previous purchases
- customer support
- analyzing customer purchasing behavior

==== Tables covered by the view:

- Product
- Client
- Order
- Product
- makes_order
- includes

==== SQL код
{{{#!sql
CREATE OR REPLACE VIEW vw_customer_order_history AS
SELECT
    c.client_id,
    c.first_name,
    c.last_name,
    c.email,

    o.order_num,
    o.quantity,
    o.status,
    o.last_modified_date,
    o.payment_method,
    o.discount,

    p.code AS product_code,
    p.description AS product_description,
    p.price

FROM client c
JOIN makes_order mo
    ON mo.client_id = c.client_id
JOIN "order" o
    ON o.order_num = mo.order_num
JOIN includes i
    ON i.order_num = o.order_num
JOIN product p
    ON p.code = i.code;

}}}

==== Logic explanation
**1.** The `client` table provides customer information.

**2.** `makes_order` connects customers with their orders.

**3.** The `order` table provides order information.

**4.** `includes` connects each order with its products.

**5.** product` provides product information.

**6.** An order containing several products produces one row for each product.

==== Reason for view 
This view is useful because:

- It provides a centralized customer purchase history
- It makes previous orders easy to retrieve
- It combines customer, order, and product information
- It simplifies customer support queries
- It can be used for purchasing behavior analysis

Without this view, every customer order-history query would have to repeat the joins between client, makes_order, order, includes, and product.