NW5- Jihad-Omer-SQL-Week2

2-exercises/cyf_ecommerce.sql

@@ -1,5 +1,6 @@
-drop table if exists order_items;
-drop table if exists orders cascade;
+ // import the data from the csv files
+drop table if exists order_items; 
+drop table if exists orders cascade; // 
 DROP TABLE IF EXISTS product_availability cascade;
 drop table if exists customers cascade;
 drop table if exists products cascade;
@@ -122,3 +123,4 @@ INSERT INTO order_items VALUES (17, 9, 6, 4, 2);
 INSERT INTO order_items VALUES (18, 10, 6, 2, 1);
 INSERT INTO order_items VALUES (19, 10, 4, 1, 5);
 
+

2-exercises/task.md

@@ -35,16 +35,74 @@ 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
+SELECT name, address FROM customers WHERE country = 'United States';
+
 2. Retrieve all the customers in ascending name sequence
+SELECT * FROM customers ORDER BY name ASC;
 3. Retrieve all the products whose name contains the word `socks`
+SELECT * FROM products WHERE lower(product_name) LIKE '%socks%';
 4. Retrieve all the products which cost more than 100 showing product id, name, unit price and supplier id.
+
+SELECT products.id, products.product_name, product_availability.unit_price, product_availability.supp_id
+FROM products
+INNER JOIN product_availability
+ON (products.id = product_availability.prod_id) 
+WHERE product_availability.unit_price > 100;
 5. Retrieve the 5 most expensive products
+SELECT products.id, products.product_name, product_availability.unit_price
+FROM products
+INNER JOIN product_availability
+ON (products.id = product_availability.prod_id)
+ORDER BY product_availability.unit_price DESC
+LIMIT 5;
 6. Retrieve all the products with their corresponding suppliers. The result should only contain the columns `product_name`, `unit_price` and `supplier_name`
+
+SELECT products.product_name, product_availability.unit_price, suppliers.supplier_name
+FROM products
+INNER JOIN product_availability
+ON products.id = product_availability.prod_id
+INNER JOIN suppliers
+ON product_availability.supp_id = suppliers.id;
+
 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`.
+
+SELECT products.product_name, suppliers.supplier_name
+FROM products
+INNER JOIN product_availability
+ON products.id = product_availability.prod_id
+INNER JOIN suppliers
+ON product_availability.supp_id = suppliers.id AND suppliers.country = 'United Kingdom';
+
 8. Retrieve all orders, including order items, from customer ID `1`. Include order id, reference, date and total cost (calculated as quantity * unit price).
+
+SELECT orders.id, orders.order_reference, orders.order_date, order_items.quantity * product_availability.unit_price AS total_cost
+FROM orders
+INNER JOIN order_items
+ON orders.id = order_items.order_id
+INNER JOIN product_availability
+ON order_items.product_id = product_availability.prod_id
+WHERE orders.customer_id = 1;
+
 9. Retrieve all orders, including order items, from customer named `Hope Crosby`
+
+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';
+
+
 10. Retrieve all the products in the order `ORD006`. The result should only contain the columns `product_name`, `unit_price` and `quantity`.
+
+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';
+
 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`.
+
+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.
+
+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'; 
+
+
 13. List all orders giving customer name, order reference, order date and order total amount (quantity * unit price) in descending order of total.
 
+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;
+

3-projects/server.js

@@ -0,0 +1,36 @@
+const express = require("express");
+const app = express();
+const { Pool } = require("pg");
+
+const db = new Pool({
+ user: "nabwa",
+ host: "localhost",
+ database: "cyf_ecommerce",
+ password: "",
+ port: 5432,
+});
+
+app.get("/customers", function (req, res) {
+ db.query("SELECT * FROM customers", (error, result) => {
+ res.json(result.rows);
+ });
+});
+
+app.get("/suppliers", function (req, res) {
+ db.query("SELECT * FROM suppliers", (error, result) => {
+ res.json(result.rows);
+ });
+});
+
+app.get("/products", (req, res) => {
+ db.query(
+ "select p.product_name, p_a.unit_price,s.supplier_name from products p join product_availability p_a on (p.id = p_a.prod_id) join suppliers s on (s.id = p_a.supp_id)",
+ (err, result) => {
+ res.json(result.rows);
+ }
+ );
+});
+
+app.listen(8080, function () {
+ console.log("Server is listening on port 8080.");
+});