How to CREATE VIEW in BigQuery

Why How to CREATE VIEW in BigQuery is important

-- Create or replace a view that shows total spend per customer
CREATE OR REPLACE VIEW `shop.analytics.customer_lifetime_value` AS
SELECT
  c.id   AS customer_id,
  c.name AS customer_name,
  SUM(o.total_amount) AS lifetime_value,
  COUNT(o.id)         AS order_count,
  MIN(o.order_date)   AS first_purchase,
  MAX(o.order_date)   AS last_purchase
FROM `shop.raw.Customers` AS c
JOIN `shop.raw.Orders`    AS o ON o.customer_id = c.id
GROUP BY customer_id, customer_name;

CREATE [OR REPLACE] [TEMP | TEMPORARY] VIEW [IF NOT EXISTS] `project.dataset.view_name`
[(column_list)]
[OPTIONS (expiration_timestamp=TIMESTAMP 'YYYY-MM-DD HH:MI:SS', description="text")]
AS
SELECT
  c.id   AS customer_id,
  c.name AS customer_name,
  DATE(o.order_date) AS order_day,
  SUM(oi.quantity * p.price) AS daily_revenue
FROM `project.raw.Customers` AS c
JOIN `project.raw.Orders`      AS o  ON o.customer_id = c.id
JOIN `project.raw.OrderItems`  AS oi ON oi.order_id   = o.id
JOIN `project.raw.Products`    AS p  ON p.id          = oi.product_id
GROUP BY customer_id, customer_name, order_day;