diff --git a/2-exercises/entity-relation-diagram.png b/2-exercises/entity-relation-diagram.png new file mode 100644 index 00000000..b58a4ca2 Binary files /dev/null and b/2-exercises/entity-relation-diagram.png differ diff --git a/2-exercises/task.md b/2-exercises/task.md index c48d2286..89914657 100644 --- a/2-exercises/task.md +++ b/2-exercises/task.md @@ -7,9 +7,9 @@ In this homework, you are going to work with an ecommerce database. In this data Below you will find a set of tasks for you to complete to set up a database for an e-commerce app. To submit this homework write the correct commands for each question here: -```sql - +``` +PLEASE SEE BELOW ``` When you have finished all of the questions - open a pull request with your answers to the `Databases-Homework` repository. @@ -30,21 +30,424 @@ psql -d cyf_ecommerce -f cyf_ecommerce.sql Open the file `cyf_ecommerce.sql` in VSCode and examine the SQL code. Take a piece of paper and draw the database with the different relationships between tables (as defined by the REFERENCES keyword in the CREATE TABLE commands). Identify the foreign keys and make sure you understand the full database schema. +Entity Relation Diagram: +![](entity-relation-diagram.png) + ## Task 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, + city, + country +FROM customers +WHERE country = 'United States'; +``` + +``` + name | address | city | country +--------------+----------------------------+------------------+--------------- + Amber Tran | 6967 Ac Road | Villafranca Asti | United States + Edan Higgins | Ap #840-3255 Tincidunt St. | Arles | United States + +``` + 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 + +``` + 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 +``` + 4. Retrieve all the products which cost more than 100 showing product id, name, unit price and supplier id. + +```sql +SELECT + p.id AS product_id, + p.product_name, + pa.unit_price, + pa.supp_id AS supplier_id +FROM products p +INNER JOIN product_availability pa +ON (p.id = pa.prod_id) +WHERE pa.unit_price > 100; +``` + +``` + product_id | product_name | unit_price | supplier_id +------------+----------------+------------+------------- + 1 | Mobile Phone X | 249 | 4 + 1 | Mobile Phone X | 299 | 1 +``` + 5. Retrieve the 5 most expensive products + +```sql +SELECT + p.product_name, + pa.unit_price +FROM products p +INNER JOIN product_availability pa +ON (p.id = pa.prod_id) +ORDER BY pa.unit_price DESC +LIMIT 5; +``` + +``` + product_name | unit_price +-----------------+------------ + Mobile Phone X | 299 + Mobile Phone X | 249 + Javascript Book | 41 + Javascript Book | 40 + Javascript Book | 39 +``` + 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 + p.product_name, + pa.unit_price, + s.supplier_name +FROM products p +INNER JOIN product_availability pa +ON (p.id = pa.prod_id) +INNER JOIN suppliers s +ON (pa.supp_id = s.id) +ORDER BY pa.unit_price; +``` + +``` + product_name | unit_price | supplier_name +-------------------------+------------+--------------- + Coffee Cup | 3 | Amazon + Coffee Cup | 4 | Taobao + Coffee Cup | 4 | Argos + Coffee Cup | 5 | Sainsburys + Super warm socks | 5 | Taobao + Super warm socks | 8 | Argos + Super warm socks | 10 | Sainsburys + Le Petit Prince | 10 | Amazon + Le Petit Prince | 10 | Sainsburys + Super warm socks | 10 | Amazon + Ball | 14 | Amazon + Ball | 15 | Sainsburys + Tee Shirt Olympic Games | 18 | Taobao + Tee Shirt Olympic Games | 20 | Amazon + Ball | 20 | Taobao + Tee Shirt Olympic Games | 21 | Argos + Javascript Book | 39 | Argos + Javascript Book | 40 | Amazon + Javascript Book | 41 | Taobao + Mobile Phone X | 249 | Sainsburys + Mobile Phone X | 299 | Amazon +``` + 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`. -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 + p.product_name, + s.supplier_name +FROM products p +INNER JOIN product_availability pa +ON (p.id = pa.prod_id) +INNER JOIN suppliers s +ON (pa.supp_id = s.id) +WHERE s.country = 'United Kingdom' +ORDER BY p.product_name; +``` + +``` + product_name | supplier_name +-------------------------+--------------- + Ball | Sainsburys + Coffee Cup | Sainsburys + Coffee Cup | Argos + Javascript Book | Argos + Le Petit Prince | Sainsburys + Mobile Phone X | Sainsburys + Super warm socks | Sainsburys + Super warm socks | Argos + Tee Shirt Olympic Games | Argos +``` + +8. Retrieve all orders, including order items, from customer ID `1`. Include order id, reference, date and total cost (calculated as quantity \* unit price). + +^These instructions are not clear, I have provided two variations: + +```sql +SELECT + c.id AS customer_id, + o.id AS order_id, + o.order_reference, + o.order_date, + pa.unit_price * oi.quantity AS total_cost +FROM customers c +INNER JOIN orders o +ON (c.id = o.customer_id) +INNER JOIN order_items oi +ON (o.id = oi.order_id) +INNER JOIN product_availability pa +ON (oi.product_id = pa.prod_id) +AND (oi.supplier_id = pa.supp_id) +INNER JOIN products p +ON (pa.prod_id = p.id) +WHERE c.id = 1; +``` + +``` + customer_id | order_id | order_reference | order_date | total_cost +-------------+----------+-----------------+------------+------------ + 1 | 1 | ORD001 | 2019-06-01 | 18 + 1 | 1 | ORD001 | 2019-06-01 | 25 + 1 | 2 | ORD002 | 2019-07-15 | 32 + 1 | 2 | ORD002 | 2019-07-15 | 10 + 1 | 3 | ORD003 | 2019-07-11 | 40 + 1 | 3 | ORD003 | 2019-07-11 | 40 +``` + +```sql +SELECT + c.id AS customer_id + o.id AS order_id, + o.order_reference, + o.order_date, + SUM(pa.unit_price * oi.quantity) AS total_cost +FROM customers c +INNER JOIN orders o +ON (c.id = o.customer_id) +INNER JOIN order_items oi +ON (o.id = oi.order_id) +INNER JOIN product_availability pa +ON (oi.product_id = pa.prod_id) +AND (oi.supplier_id = pa.supp_id) +INNER JOIN products p +ON (pa.prod_id = p.id) +WHERE c.id = 1 +GROUP BY c.id, o.id; +``` + +``` + customer_id | order_id | order_reference | order_date | total_cost +-------------+----------+-----------------+------------+------------ + 1 | 1 | ORD001 | 2019-06-01 | 43 + 1 | 2 | ORD002 | 2019-07-15 | 42 + 1 | 3 | ORD003 | 2019-07-11 | 80 +``` + 9. Retrieve all orders, including order items, from customer named `Hope Crosby` + +```sql +SELECT + c.name AS customer_name, + o.id AS order_id, + o.order_reference, + o.order_date, + p.id AS product_id, + p.product_name, + pa.unit_price AS product_price, + oi.quantity, + s.supplier_name, + s.country AS supplier_country +FROM customers c +INNER JOIN orders o +ON (c.id = o.customer_id) +INNER JOIN order_items oi +ON (o.id = oi.order_id) +INNER JOIN product_availability pa +ON (oi.product_id = pa.prod_id) +AND (oi.supplier_id = pa.supp_id) +INNER JOIN products p +ON (pa.prod_id = p.id) +INNER JOIN suppliers s +ON (pa.supp_id = s.id) +WHERE name = 'Hope Crosby'; +``` + +``` + customer_name | order_id | order_reference | order_date | product_id | product_name | product_price | quantity | supplier_name | supplier_country +---------------+----------+-----------------+------------+------------+----------------+---------------+----------+---------------+------------------ + Hope Crosby | 4 | ORD004 | 2019-05-24 | 1 | Mobile Phone X | 299 | 1 | Amazon | United States +``` + 10. Retrieve all the products in the order `ORD006`. The result should only contain the columns `product_name`, `unit_price` and `quantity`. + +I deliberately added the order_reference column for visual clarity. + +```sql +SELECT + o.order_reference, + p.product_name, + pa.unit_price, + oi.quantity +FROM customers c +INNER JOIN orders o +ON (c.id = o.customer_id) +INNER JOIN order_items oi +ON (o.id = oi.order_id) +INNER JOIN product_availability pa +ON (oi.product_id = pa.prod_id) +AND (oi.supplier_id = pa.supp_id) +INNER JOIN products p +ON (pa.prod_id = p.id) +INNER JOIN suppliers s +ON (pa.supp_id = s.id) +WHERE order_reference = 'ORD006'; +``` + +``` + order_reference | product_name | unit_price | quantity +-----------------+------------------+------------+---------- + ORD006 | Super warm socks | 10 | 3 + ORD006 | Le Petit Prince | 10 | 1 + ORD006 | Javascript Book | 41 | 1 + ORD006 | Coffee Cup | 4 | 3 +``` + 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 +INNER JOIN orders o +ON (c.id = o.customer_id) +INNER JOIN order_items oi +ON (o.id = oi.order_id) +INNER JOIN product_availability pa +ON (oi.product_id = pa.prod_id) +AND (oi.supplier_id = pa.supp_id) +INNER JOIN products p +ON (pa.prod_id = p.id) +INNER JOIN suppliers s +ON (pa.supp_id = s.id); +``` + +``` + name | order_reference | order_date | product_name | supplier_name | quantity +--------------------+-----------------+------------+-------------------------+---------------+---------- + Guy Crawford | ORD001 | 2019-06-01 | Tee Shirt Olympic Games | Taobao | 1 + Guy Crawford | ORD001 | 2019-06-01 | Super warm socks | Taobao | 5 + Guy Crawford | ORD002 | 2019-07-15 | Super warm socks | Argos | 4 + Guy Crawford | ORD002 | 2019-07-15 | Le Petit Prince | Sainsburys | 1 + Guy Crawford | ORD003 | 2019-07-11 | Coffee Cup | Argos | 10 + Guy Crawford | ORD003 | 2019-07-11 | Ball | Taobao | 2 + Hope Crosby | ORD004 | 2019-05-24 | Mobile Phone X | Amazon | 1 + Britanney Kirkland | ORD005 | 2019-05-30 | Javascript Book | Argos | 2 + Britanney Kirkland | ORD005 | 2019-05-30 | Le Petit Prince | Amazon | 1 + Amber Tran | ORD006 | 2019-07-05 | Coffee Cup | Taobao | 3 + Amber Tran | ORD006 | 2019-07-05 | Javascript Book | Taobao | 1 + Amber Tran | ORD006 | 2019-07-05 | Le Petit Prince | Sainsburys | 1 + Amber Tran | ORD006 | 2019-07-05 | Super warm socks | Sainsburys | 3 + Amber Tran | ORD007 | 2019-04-05 | Super warm socks | Argos | 15 + Edan Higgins | ORD008 | 2019-07-23 | Tee Shirt Olympic Games | Amazon | 1 + Edan Higgins | ORD008 | 2019-07-23 | Mobile Phone X | Sainsburys | 1 + Edan Higgins | ORD009 | 2019-07-24 | Ball | Sainsburys | 2 + Edan Higgins | ORD010 | 2019-05-10 | Ball | Taobao | 1 + Edan Higgins | ORD010 | 2019-05-10 | Super warm socks | Amazon | 5 +``` + 12. Retrieve the names of all customers who bought a product from a supplier based in China. -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 AS customer_name, + s.country AS supplier_country +FROM customers c +INNER JOIN orders o +ON (c.id = o.customer_id) +INNER JOIN order_items oi +ON (o.id = oi.order_id) +INNER JOIN product_availability pa +ON (oi.product_id = pa.prod_id) +AND (oi.supplier_id = pa.supp_id) +INNER JOIN suppliers s +ON (pa.supp_id = s.id) +WHERE s.country = 'China' +GROUP BY c.name, s.country; +``` + +``` + customer_name | supplier_country +---------------+------------------ + Amber Tran | China + Edan Higgins | China + Guy Crawford | China +``` + +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 AS customer_name, + o.order_reference, + o.order_date, + SUM(pa.unit_price * oi.quantity) AS order_total_amount +FROM customers c +INNER JOIN orders o +ON (c.id = o.customer_id) +INNER JOIN order_items oi +ON (o.id = oi.order_id) +INNER JOIN product_availability pa +ON (oi.product_id = pa.prod_id) +AND (oi.supplier_id = pa.supp_id) +INNER JOIN products p +ON (pa.prod_id = p.id) +GROUP BY o.id, c.name +ORDER BY order_total_amount DESC; +``` + +``` + customer_name | order_reference | order_date | order_total_amount +--------------------+-----------------+------------+-------------------- + Hope Crosby | ORD004 | 2019-05-24 | 299 + Edan Higgins | ORD008 | 2019-07-23 | 269 + Amber Tran | ORD007 | 2019-04-05 | 120 + Amber Tran | ORD006 | 2019-07-05 | 93 + Britanney Kirkland | ORD005 | 2019-05-30 | 88 + Guy Crawford | ORD003 | 2019-07-11 | 80 + Edan Higgins | ORD010 | 2019-05-10 | 70 + Guy Crawford | ORD001 | 2019-06-01 | 43 + Guy Crawford | ORD002 | 2019-07-15 | 42 + Edan Higgins | ORD009 | 2019-07-24 | 30 +``` diff --git a/3-projects/cyf-ecommerce-api/.gitignore b/3-projects/cyf-ecommerce-api/.gitignore new file mode 100644 index 00000000..25c8fdba --- /dev/null +++ b/3-projects/cyf-ecommerce-api/.gitignore @@ -0,0 +1,2 @@ +node_modules +package-lock.json \ No newline at end of file diff --git a/3-projects/cyf-ecommerce-api/package.json b/3-projects/cyf-ecommerce-api/package.json new file mode 100644 index 00000000..804a5780 --- /dev/null +++ b/3-projects/cyf-ecommerce-api/package.json @@ -0,0 +1,20 @@ +{ + "name": "cyf-ecommerce-api", + "version": "1.0.0", + "description": "", + "main": "index.js", + "scripts": { + "start": "node server.js", + "dev": "nodemon server.js" + }, + "keywords": [], + "author": "", + "license": "ISC", + "dependencies": { + "express": "^4.18.2", + "pg": "^8.10.0" + }, + "devDependencies": { + "nodemon": "^2.0.22" + } +} diff --git a/3-projects/cyf-ecommerce-api/project-screenshot.png b/3-projects/cyf-ecommerce-api/project-screenshot.png new file mode 100644 index 00000000..bf695137 Binary files /dev/null and b/3-projects/cyf-ecommerce-api/project-screenshot.png differ diff --git a/3-projects/cyf-ecommerce-api/public/elephant.png b/3-projects/cyf-ecommerce-api/public/elephant.png new file mode 100644 index 00000000..94612cfe Binary files /dev/null and b/3-projects/cyf-ecommerce-api/public/elephant.png differ diff --git a/3-projects/cyf-ecommerce-api/public/index.html b/3-projects/cyf-ecommerce-api/public/index.html new file mode 100644 index 00000000..725833cf --- /dev/null +++ b/3-projects/cyf-ecommerce-api/public/index.html @@ -0,0 +1,25 @@ + + + + + + + PostgreSQL API - Ecommerce + + +
+ +

PostgreSQL API - Ecommerce

+
+
+

Links to API Routes :

+ +
+
+

Buttons to Formatted Output :

+ +
+
+ + + diff --git a/3-projects/cyf-ecommerce-api/public/script.js b/3-projects/cyf-ecommerce-api/public/script.js new file mode 100644 index 00000000..7893e078 --- /dev/null +++ b/3-projects/cyf-ecommerce-api/public/script.js @@ -0,0 +1,33 @@ +const paths = ["customers", "suppliers", "products"]; + +paths.forEach((path) => { + const navLinks = document.getElementById("nav-links"); + const link = document.createElement("a"); + link.href = `/${path}`; + link.innerText = `/${path}`; + navLinks.appendChild(link); + + const navButtons = document.getElementById("nav-buttons"); + const button = document.createElement("button"); + button.id = `${path}`; + button.innerText = `/${path}`; + button.addEventListener("click", (event) => fetchAndFormat(event.target.id)); + navButtons.appendChild(button); +}); + +async function fetchAndFormat(path) { + try { + const response = await fetch(`/${path}`); + const data = await response.json(); + const outputContainer = document.getElementById("output-container"); + outputContainer.innerText = ""; + const pre = document.createElement("pre"); + const code = document.createElement("code"); + code.id = "output-json"; + code.innerText = JSON.stringify(data, null, 2); + pre.appendChild(code); + outputContainer.appendChild(pre); + } catch (error) { + console.log(error); + } +} diff --git a/3-projects/cyf-ecommerce-api/public/style.css b/3-projects/cyf-ecommerce-api/public/style.css new file mode 100644 index 00000000..d25a897f --- /dev/null +++ b/3-projects/cyf-ecommerce-api/public/style.css @@ -0,0 +1,70 @@ +* { + box-sizing: border-box; + font-family: system-ui, sans-serif; + color: black; + font-size: 16px; + font-weight: 400; +} + +body { + display: grid; + background-color: hsl(0, 0%, 92%); + max-width: 500px; + margin: 0 auto; + row-gap: 10px; +} + +header { + display: flex; + align-items: center; + gap: 20px; + border-bottom: 1px solid hsl(207, 47%, 39%); + padding: 5px; +} + +header > img { + max-width: 40px; + max-height: 40px; +} + +header > h1 { + margin: 0; + font-size: 24px; + font-weight: 600; +} + +h2 { + margin: 0; + font-size: 18px; + font-weight: 600; +} + +nav { + display: flex; + flex-wrap: wrap; + gap: 10px; + padding: 5px; +} + +button { + background-color: hsl(207, 47%, 39%); + color: hsl(0, 0%, 90%); + border: none; + border-radius: 2px; + padding: 5px 8px; + cursor: pointer; +} + +button:hover { + background-color: hsl(207, 47%, 49%); +} + +#output-container { + background-color: hsl(0, 0%, 95%); + border: 1px solid darkgray; + padding: 0 10px; +} + +#output-json { + font-family: monospace; +} diff --git a/3-projects/cyf-ecommerce-api/readme.md b/3-projects/cyf-ecommerce-api/readme.md new file mode 100644 index 00000000..8cf41f19 --- /dev/null +++ b/3-projects/cyf-ecommerce-api/readme.md @@ -0,0 +1,28 @@ +# PostgreSQL Ecommerce API + +## Screenshot: + +![](project-screenshot.png) + +## Instructions: + +1. clone this repo +2. install [postgresql](https://www.postgresql.org/) +3. inside the root of the repository, open a terminal: +4. move into the `2-exercises` folder: + `cd 2-exercises` +5. create the database + `createdb cyf_ecommerce` +6. populate the database + `createdb -d cyf_ecommerce -f cyf-cyf_ecommerce.sql` +7. move to the api directory: + `cd ../3-projects/cyf-ecommerce-api` +8. install the project dependencies: + `npm install` +9. start the server in develoment mode: + `npm run dev` +10. visit http://localhost:3000 + +**Note: this project assumes you are connecting to the database with:** +`username: postgres` +`password: password` diff --git a/3-projects/cyf-ecommerce-api/server.js b/3-projects/cyf-ecommerce-api/server.js new file mode 100644 index 00000000..92791709 --- /dev/null +++ b/3-projects/cyf-ecommerce-api/server.js @@ -0,0 +1,63 @@ +const express = require("express"); +const app = express(); + +app.use(express.static("public")); + +const { Pool } = require("pg"); + +const db = new Pool({ + user: "postgres", + host: "localhost", + database: "cyf_ecommerce", + password: "password", + port: 5432, +}); + +app.get("/customers", (req, res) => { + db.query("SELECT * FROM customers") + .then((result) => { + res.json(result.rows); + }) + .catch((error) => { + console.log(error); + }); +}); + +app.get("/suppliers", (req, res) => { + db.query("SELECT * FROM suppliers") + .then((result) => { + res.json(result.rows); + }) + .catch((error) => { + console.log(error); + }); +}); + +app.get("/products", (req, res) => { + db.query( + `SELECT + p.product_name, + pa.unit_price, + s.supplier_name + FROM product_availability pa + INNER JOIN products p + ON (pa.prod_id = p.id) + INNER JOIN suppliers s + ON (pa.supp_id = s.id) + ORDER BY p.product_name, pa.unit_price;` + ) + .then((result) => { + res.json(result.rows); + }) + .catch((error) => { + console.log(error); + }); +}); + +app.get("/", (req, res) => { + res.sendFile(__dirname + "./public/index.html"); +}); + +app.listen(3000, () => { + console.log("The server is running on port 3000"); +});