NW5_Manchester_M.Barry_SQL-Coursework-week2

2-exercises/task.md

@@ -35,16 +35,176 @@ Open the file `cyf_ecommerce.sql` in VSCode and examine the SQL code. Take a pie
 Once you understand the database that you are going to work with, solve the following challenge by writing SQL queries using everything you learned about SQL:
 
 1. Retrieve all the customers' names and addresses who live in the United States
+```sql
+SELECT name, address FROM customers WHERE country = 'United States';
+ name | address
+--------------+----------------------------
+ Amber Tran | 6967 Ac Road
+ Edan Higgins | Ap #840-3255 Tincidunt St.
+(2 rows)
+```
 2. Retrieve all the customers in ascending name sequence
+```sql
+SELECT * FROM customers ORDER BY name;
+ id | name | address | city | country 
+----+--------------------+-----------------------------+------------------+----------------
+ 4 | Amber Tran | 6967 Ac Road | Villafranca Asti | United States
+ 3 | Britanney Kirkland | P.O. Box 577, 5601 Sem, St. | Little Rock | United Kingdom
+ 5 | Edan Higgins | Ap #840-3255 Tincidunt St. | Arles | United States
+ 1 | Guy Crawford | 770-2839 Ligula Road | Paris | France
+ 2 | Hope Crosby | P.O. Box 276, 4976 Sit Rd. | Steyr | United Kingdom
+ 6 | Quintessa Austin | 597-2737 Nunc Rd. | Saint-Marc | United Kingdom
+(6 rows)
+```
 3. Retrieve all the products whose name contains the word `socks`
+```sql
+SELECT * FROM products WHERE product_name like '%socks%';
+ id | product_name 
+----+------------------
+ 4 | Super warm socks
+(1 row)
+```
 4. Retrieve all the products which cost more than 100 showing product id, name, unit price and supplier id.
+```sql
+SELECT p.id, p.product_name, pa.unit_price, pa.supp_id FROM products p JOIN product_availability pa ON (p.id = pa.prod_id) WHERE pa.unit_price > 100;
+ id | product_name | unit_price | supp_id 
+----+----------------+------------+---------
+ 1 | Mobile Phone X | 249 | 4
+ 1 | Mobile Phone X | 299 | 1
+(2 rows)
+```
 5. Retrieve the 5 most expensive products
+```sql
+SELECT * FROM product_availability ORDER BY unit_price DESC limit 5;
+ prod_id | supp_id | unit_price 
+---------+---------+------------
+ 1 | 1 | 299
+ 1 | 4 | 249
+ 2 | 2 | 41
+ 2 | 1 | 40
+ 2 | 3 | 39
+(5 rows)
+```
+
 6. Retrieve all the products with their corresponding suppliers. The result should only contain the columns `product_name`, `unit_price` and `supplier_name`
+```sql
+SELECT product_name, unit_price, supplier_name FROM products JOIN product_availability ON (products.id = product_availability.prod_id) JOIN suppliers ON (product_availability.supp_id = suppliers.id);
+ product_name | unit_price | supplier_name 
+-------------------------+------------+---------------
+ Mobile Phone X | 249 | Sainsburys 
+ Mobile Phone X | 299 | Amazon 
+ Javascript Book | 41 | Taobao 
+ Javascript Book | 39 | Argos
+ Javascript Book | 40 | Amazon 
+ Le Petit Prince | 10 | Sainsburys 
+ Le Petit Prince | 10 | Amazon 
+ Super warm socks | 10 | Sainsburys 
+ Super warm socks | 8 | Argos
+ Super warm socks | 5 | Taobao 
+ Super warm socks | 10 | Amazon 
+ Coffee Cup | 5 | Sainsburys 
+ Coffee Cup | 4 | Argos
+ Coffee Cup | 4 | Taobao 
+ Coffee Cup | 3 | Amazon
+ Ball | 20 | Taobao
+ Ball | 15 | Sainsburys
+ Ball | 14 | Amazon
+ Tee Shirt Olympic Games | 21 | Argos
+ Tee Shirt Olympic Games | 18 | Taobao
+ Tee Shirt Olympic Games | 20 | Amazon
+(21 rows)
+```
+
 7. Retrieve all the products sold by suppliers based in the United Kingdom. The result should only contain the columns `product_name` and `supplier_name`.
+```sql
+SELECT p.product_name, s.supplier_name FROM products p JOIN product_availability pa ON (p.id = pa.prod_id) JOIN suppliers s ON (s.id = pa.supp_id) WHERE s.country = 'United Kingdom'; 
+ product_name | supplier_name 
+-------------------------+---------------
+ Javascript Book | Argos
+ Super warm socks | Argos
+ Coffee Cup | Argos
+ Tee Shirt Olympic Games | Argos
+ Mobile Phone X | Sainsburys
+ Le Petit Prince | Sainsburys
+ Super warm socks | Sainsburys
+ Coffee Cup | Sainsburys
+ Ball | Sainsburys
+(9 rows)
+```
 8. Retrieve all orders, including order items, from customer ID `1`. Include order id, reference, date and total cost (calculated as quantity * unit price).
+```sql
+SELECT o.customer_id, o.id AS "Oder ID", o.order_reference, o.order_date, oi.quantity*pa.unit_price AS "total cost" FROM product_availability pa JOIN order_items oi ON (pa.prod_id = oi.product_id) JOIN orders o ON (o.id = oi.order_id) WHERE o.customer_id = 1;
+ customer_id | Oder ID | order_reference | order_date | total cost 
+-------------+---------+-----------------+------------+------------
+ 1 | 1 | ORD001 | 2019-06-01 | 20 
+ 1 | 1 | ORD001 | 2019-06-01 | 18 
+ 1 | 1 | ORD001 | 2019-06-01 | 21 
+ 1 | 1 | ORD001 | 2019-06-01 | 50 
+ 1 | 1 | ORD001 | 2019-06-01 | 25 
+ 1 | 1 | ORD001 | 2019-06-01 | 40 
+ 1 | 1 | ORD001 | 2019-06-01 | 50 
+ 1 | 2 | ORD002 | 2019-07-15 | 40 
+ 1 | 2 | ORD002 | 2019-07-15 | 20 
+ 1 | 2 | ORD002 | 2019-07-15 | 32 
+ 1 | 2 | ORD002 | 2019-07-15 | 40 
+ 1 | 2 | ORD002 | 2019-07-15 | 10 
+ 1 | 2 | ORD002 | 2019-07-15 | 10 
+ 1 | 3 | ORD003 | 2019-07-11 | 30 
+ 1 | 3 | ORD003 | 2019-07-11 | 40 
+ 1 | 3 | ORD003 | 2019-07-11 | 40
+ 1 | 3 | ORD003 | 2019-07-11 | 50
+ 1 | 3 | ORD003 | 2019-07-11 | 28
+ 1 | 3 | ORD003 | 2019-07-11 | 40
+ 1 | 3 | ORD003 | 2019-07-11 | 30
+(20 rows)
+
+```
 9. Retrieve all orders, including order items, from customer named `Hope Crosby`
+```sql
+SELECT c.name, o.id, oi.id, oi.quantity, c.address, c.city, c.country FROM customers c JOIN orders o ON (c.id = o.customer_id) JOIN order_items oi ON (o.id = oi.order_id) WHERE c.name = 'Hope Crosby';
+ name | id | id | quantity | address | city | country 
+-------------+----+----+----------+----------------------------+-------+----------------
+ Hope Crosby | 4 | 7 | 1 | P.O. Box 276, 4976 Sit Rd. | Steyr | United Kingdom 
+(1 row)
+```
 10. Retrieve all the products in the order `ORD006`. The result should only contain the columns `product_name`, `unit_price` and `quantity`.
+```sql
+SELECT p.product_name, pa.unit_price, oi.quantity FROM products p JOIN product_availability pa ON (p.id = pa.prod_id) JOIN order_items oi ON (oi.product_id = pa.prod_id) JOIN orders o ON (o.id = oi.order_id) WHERE o.order_reference = 'ORD006';
+ product_name | unit_price | quantity 
+------------------+------------+----------
+ Coffee Cup | 3 | 3
+ Coffee Cup | 4 | 3
+ Coffee Cup | 4 | 3
+ Coffee Cup | 5 | 3
+ Javascript Book | 40 | 1
+ Javascript Book | 41 | 1
+ Javascript Book | 39 | 1
+ Le Petit Prince | 10 | 1
+ Le Petit Prince | 10 | 1
+ Super warm socks | 10 | 3
+ Super warm socks | 5 | 3
+ Super warm socks | 8 | 3
+ Super warm socks | 10 | 3
+(13 rows)
+```
 11. Retrieve all the products with their supplier for all orders of all customers. The result should only contain the columns `name` (from customer), `order_reference`, `order_date`, `product_name`, `supplier_name` and `quantity`.
+```sql
+SELECT c.name, o.order_reference, o.order_date, p.product_name, s.supplier_name, oi.quantity FROM customers c JOIN orders o ON (c.id = o.customer_id) JOIN order_items oi ON (o.id = oi.order_id) JOIN suppliers s ON (oi.supplier_id = s.id) JOIN product_availability pa ON (s.id = pa.supp_id) JOIN products p ON (p.id = pa.prod_id);
+```
 12. Retrieve the names of all customers who bought a product from a supplier based in China.
+```sql
+SELECT c.name FROM customers c JOIN orders o ON (c.id = o.customer_id) JOIN order_items oi ON (o.id = oi.order_id) JOIN suppliers s ON (oi.supplier_id = s.id) WHERE s.country = 'China'; 
+ name 
+--------------
+ Guy Crawford 
+ Guy Crawford 
+ Guy Crawford 
+ Amber Tran 
+ Amber Tran 
+ Edan Higgins 
+(6 rows) 
+```
 13. List all orders giving customer name, order reference, order date and order total amount (quantity * unit price) in descending order of total.
-
+```sql
+SELECT c.name, o.order_reference, o.order_date, oi.quantity * pa.unit_price AS TOTAL_AMOUNT FROM customers c JOIN orders o ON ( c.id = o.customer_id) JOIN order_items oi ON (o.id = oi.order_id) JOIN product_availability pa ON (oi.product_id = pa.prod_id) ORDER BY TOTAL_AMOUNT DESC;
+```