Mickey Haile-SQL-coursework-WEEK1

week-1/mandatory/2-classes-db/task.md

@@ -19,18 +19,41 @@ If you haven't completed all the exercises from this lesson then do that first.
 
 ### Tasks
 1.  Which rooms have a rate of more than 100.00?
+SELECT * FROM rooms WHERE rate > 100;
 2.  List the reservations that have a checkin date this month and are for more than three nights.
+SELECT * FROM reservations 
+ WHERE (checkIn_date between '2023-01-01'and '2023-01-31') and (checkOut_date - checkIn_date > 3);
 3.  List all customers from cities that begin with the letter 'M'.
+SELECT city FROM customers 
+WHERE city LIKE 'M%'
+ ;
 
 Insert some new data into the room_types and rooms tables, querying after each stage to check the data, as follows:
 
-4.  Make a new room type of PENTHOUSE with a default rate of £185.00
+4.  Make a new room type of PENTHOUSE with a default rate of £185.00.
+INSERT INTO room_types (room_type, def_rate) VALUES ('PENTHOUSE', '185');
 5.  Add new rooms, 501 and 502 as room type PENTHOUSE and set the room rate of each to the default value (as in the new room type).
+INSERT INTO rooms (room_no, rate, room_type) VALUES ('501','185','PENTHOUSE')
+INSERT INTO rooms (room_no, rate, room_type) VALUES ('502','185','PENTHOUSE');
 6.  Add a new room 503 as a PREMIER PLUS type similar to the other PREMIER PLUS rooms in the hotel but with a room rate of 143.00 to reflect its improved views over the city.
+Insert into rooms (room_no,rate, room_type) VALUES ('503','143','PREMIER PLUS');
 
 Using what you can learn about aggregate functions in the w3schools SQL classes (or other providers), try:
 
 7.  The hotel manager wishes to know how many rooms were occupied any time during the previous month - find that information.
+SELECT count(id) FROM reservations WHERE (checkIn_date between '2022-12-01'and '2022-12-31')
+
+
 8.  Get the total number of nights that customers stayed in rooms on the second floor (rooms 201 - 299).
+SELECT SUM(checkOut_date - checkIn_date) AS total_nights FROM reservations WHERE room_no between 200 and 299;
 9.  How many invoices are for more than £300.00 and what is their grand total and average amount?
+SELECT COUNT(total) from invoices WHERE total > 300;
+SELECT SUM(total) from invoices WHERE total > 300;
 10.  Bonus Question: list the number of nights stay for each floor of the hotel (floor no is the hundreds part of room number, e.g. room **3**12 is on floor **3**)
+ Floor 1- 54 - select sum(checkOut_date -checkIn_date) from reservations where room_no between 100 and 199;
+
+    Floor 2- 63 - select sum(checkOut_date -checkIn_date) from reservations where room_no between 200 and 299;
+
+    Floor 3- 46- select sum(checkOut_date -checkIn_date) from reservations where room_no between 300 and 399;
+
+    Floor 4- 40 - select sum(checkOut_date -checkIn_date) from reservations where room_no between 400 and 499;

week-2/mandatory/2-ecommerce-db/task.md

@@ -35,16 +35,61 @@ 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 product_name ILIKE '%socks%';
+
 4. Retrieve all the products which cost more than 100 showing product id, name, unit price and supplier id.
-5. Retrieve the 5 most expensive products
-6. Retrieve all the products with their corresponding suppliers. The result should only contain the columns `product_name`, `unit_price` and `supplier_name`
+
+SELECT p.product_name, p.id, pa.prod_id, pa.supp_id, pa.unit_price from products p JOIN product_availability pa on (p.id = pa.prod_id) where pa.unit_price > 100;
+
+5. Retrieve the 5 most expensive products.
+
+ SELECT p.product_name, pa.unit_price from products p JOIN product_availability pa on (p.id = pa.prod_id) ORDER BY pa.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 p.product_name, pa.unit_price, s.supplier_name FROM products p JOIN product_availability pa ON (p.id = pa.prod_id) JOIN suppliers s ON(pa.prod_id = s.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 p.product_name, s.supplier_name FROM products p JOIN suppliers s ON (p.id = s.id) WHERE s.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).
-9. Retrieve all orders, including order items, from customer named `Hope Crosby`
+
+SELECT o.order_date, o.order_reference, o.id, (or_item.quantity \* pa.unit_price) AS "total cost" FROM orders o JOIN customers c on(o.customer_id = c.id) JOIN order_items or_item ON (o.id = or_item.order_id) JOIN product_availability pa ON (or_item.product_id = pa.prod_id) WHERE c.id = 1;
+
+9. Retrieve all orders, including order items, from customer named `Hope Crosby`.
+
+SELECT o.order_date, o.order_reference, o.id, (or_item.quantity \* pa.unit_price) as "total cost" FROM orders o JOIN customers c on(o.customer_id = c.id) JOIN order_items or_item ON (o.id = or_item.order_id) JOIN product_availability pa ON (or_item.product_id = pa.prod_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, ori.quantity FROM products p JOIN product_availability pa ON (p.id = pa.prod_id) JOIN order_items ori ON (product_id = p.id) JOIN orders o ON (o.id = ori.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, ori.quantity FROM customers c JOIN orders o ON(c.id = o.customer_id) JOIN order_items ori ON (ori.order_id = o.id) JOIN products p ON(p.id = product_id) JOIN suppliers s ON(s.id = ori.supplier_id);
+
 12. Retrieve the names of all customers who bought a product from a supplier based in China.
+
+  SELECT c.name, s.country FROM customers c JOIN orders o on (o.customer_id =c.id ) JOIN order_items i on (i.order_id = o.id) JOIN suppliers s ON(s.id = i.supplier_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, sum(ori.quantity \* pa.unit_price) AS "total amount" FROM customers c JOIN orders o ON(c.id = o.customer_id) JOIN order_items ori ON (ori.order_id = o.id) JOIN product_availability pa ON (pa.prod_id = ori.product_id and pa.supp_id = ori.supplier_id) GROUP by c.name, o.order_reference, o.order_date ORDER BY "total amount" DESC;
+

week-2/mandatory/cyf-hotels-api/package.json

@@ -0,0 +1,11 @@
+{
+  "name": "server.js",
+  "version": "1.0.0",
+  "description": "",
+  "main": "server.js",
+  "scripts": {
+    "test": "echo \"Error: no test specified\" && exit 1"
+  },
+  "author": "",
+  "license": "ISC"
+}

week-2/mandatory/cyf-hotels-api/server.js

@@ -0,0 +1,42 @@
+const express = require("express");
+const app = express();
+
+app.listener = app.listen(port, function () {
+  console.log(`Server is listening on port ${port}`);
+});
+const { Pool } = require("pg");
+
+const db = new Pool({
+  user: "mickeyhaile", // replace with you username
+  host: "localhost",
+  database: "cyf_hotels",
+  password: "",
+  port: 5432,
+});
+
+app.get("/customers", function (req, res) {
+  db.query("SELECT id, name, city, phone FROM customers")
+    .then((result) => {
+      res.json(result.rows);
+    })
+    .catch((error) => {
+      console.log(error);
+    });
+});
+app.get("/products", function (req, res) {
+  db.query("SELECT id, name, city, phone FROM customers")
+    .then((result) => {
+      res.json(result.rows);
+    })
+    .catch((error) => {
+      console.log(error);
+    });
+});
+app.get("/suppliers", function (req, res) {
+  db.query(
+    "SELECT p.product_name, pa.unit_price, 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 )",
+    (error, result) => {
+      console.log(result);
+      res.json(result.rows);
+    });
+});