E-commerce store, including Restful API service with JWT,deploy with nginx+unicorn ,redis,memcache,postgresql
def customer_like_categories
self.joins('INNER JOIN orders ON customers.id=orders.customer_id INNER JOIN line_items ON orders.id=line_items.order_id INNER JOIN products ON products.id=line_items.product_id INNER JOIN categories ON categories.id=products.category_id').
select("DISTINCT customers.id AS customer_id,customers.first_name AS customer_first_name,categories.id AS category_id,categories.name AS category_name").
order("customer_first_name,category_name")
end +-------------+---------------------+-------------+-------------------------+
| customer_id | customer_first_name | category_id | category_name |
+-------------+---------------------+-------------+-------------------------+
| 5 | Adam | 215 | Jackets & Coats |
| 1 | John | 4 | Cooker & Steamer |
| 3 | Kiten | 323 | Bakeware |
| 3 | Kiten | 486 | Gaming Headsets |
| 3 | Kiten | 420 | Smart Riding Equipments |
| 2 | Peter | 52 | Android Tablet |
| 2 | Peter | 105 | Earbud Headphones |
| 2 | Peter | 509 | Safety warning device |
| 4 | Wooden | 503 | GPS Navigation |
| 4 | Wooden | 298 | LED Watches |
| 4 | Wooden | 545 | US--LA Warehouse |
+-------------+---------------------+-------------+-------------------------+
Find how many customers(NewCustomers, repeatCustomers) who orders on the basis of previous and current month
+-------------+---------------------------+
| customer_id | created_at |
+-------------+---------------------------+
| 1 | 2015-04-05 15:48:11 +0800 |
| 2 | 2015-04-01 10:18:21 +0800 |
| 3 | 2013-09-25 10:39:20 +0800 |
| 4 | 2013-10-04 10:39:20 +0800 |
| 5 | 2013-11-20 10:39:20 +0800 |
| 6 | 2012-10-04 10:39:20 +0800 |
| 7 | 2014-07-04 10:39:20 +0800 |
| 8 | 2015-01-04 10:39:20 +0800 |
| 2 | 2015-01-13 20:18:41 +0800 |
| 3 | 2014-10-08 10:39:20 +0800 |
| 4 | 2015-01-28 12:38:59 +0800 |
| 4 | 2015-04-06 10:39:20 +0800 |
+-------------+---------------------------+
def new_vs_reccuring_customers
sql="SELECT date_part('year',o.created_at) AS year, date_part('month',o.created_at) AS month,COUNT(DISTINCT o.customer_id) AS total,COUNT(CASE WHEN o.created_at = oo.min_created THEN o.customer_id END) AS new_customer_count,COUNT(DISTINCT o.customer_id)-COUNT(CASE WHEN o.created_at = oo.min_created THEN o.customer_id END) AS reccuring_customer_count
FROM orders o JOIN
(SELECT customer_id, MIN(created_at) AS min_created
FROM orders
GROUP BY customer_id
) oo
ON o.customer_id = oo.customer_id
GROUP BY date_part('year',o.created_at), date_part('month',o.created_at)
ORDER BY date_part('year',o.created_at), date_part('month',o.created_at)"
self.find_by_sql(sql)
end+------+-------+-------+--------------------+--------------------------+
| year | month | total | new_customer_count | reccuring_customer_count |
+------+-------+-------+--------------------+--------------------------+
| 2012 | 10 | 1 | 1 | 0 |
| 2013 | 9 | 1 | 1 | 0 |
| 2013 | 10 | 1 | 1 | 0 |
| 2013 | 11 | 1 | 1 | 0 |
| 2014 | 7 | 1 | 1 | 0 |
| 2014 | 10 | 1 | 0 | 1 |
| 2015 | 1 | 3 | 2 | 1 |
| 2015 | 4 | 3 | 1 | 2 |
+------+-------+-------+--------------------+--------------------------+
+----+-------------+
| id | customer_id |
+----+-------------+
| 1 | 1 |
| 2 | 2 |
| 3 | 3 |
| 4 | 4 |
| 5 | 5 |
| 6 | 6 |
| 7 | 7 |
| 8 | 8 |
| 9 | 2 |
| 10 | 3 |
| 11 | 4 |
| 12 | 4 |
+----+-------------+
def customers_count_by_order_count
query="SELECT t.orders_count,COUNT(t.orders_count) AS customers_count, CONCAT(CAST(ROUND(100.0 * (COUNT(t.orders_count)/SUM(COUNT(t.orders_count)) OVER ()), 1) AS text),'%') AS percentage FROM (SELECT orders.customer_id,COUNT(orders.customer_id) AS orders_count FROM orders GROUP BY orders.customer_id ORDER BY orders.customer_id) AS t GROUP BY t.orders_count ORDER BY t.orders_count"
self.find_by_sql(query)
end+--------------+-----------------+------------+
| orders_count | customers_count | percentage |
+--------------+-----------------+------------+
| 1 | 5 | 62.5% |
| 2 | 2 | 25.0% |
| 3 | 1 | 12.5% |
+--------------+-----------------+------------+