diff --git a/week-3/mandatory/.gitignore b/week-3/mandatory/.gitignore
new file mode 100644
index 00000000..30bc1627
--- /dev/null
+++ b/week-3/mandatory/.gitignore
@@ -0,0 +1 @@
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\ No newline at end of file
diff --git a/week-3/mandatory/package-lock.json b/week-3/mandatory/package-lock.json
new file mode 100644
index 00000000..b2788bd2
--- /dev/null
+++ b/week-3/mandatory/package-lock.json
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+        "escape-html": "~1.0.3",
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+        "range-parser": "~1.2.1",
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+        "encodeurl": "~1.0.2",
+        "escape-html": "~1.0.3",
+        "parseurl": "~1.3.3",
+        "send": "0.17.1"
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+}
diff --git a/week-3/mandatory/package.json b/week-3/mandatory/package.json
new file mode 100644
index 00000000..ab9e507f
--- /dev/null
+++ b/week-3/mandatory/package.json
@@ -0,0 +1,17 @@
+{
+  "name": "week-3",
+  "version": "1.0.0",
+  "main": "index.js",
+  "scripts": {
+    "test": "echo \"Error: no test specified\" && exit 1"
+  },
+  "keywords": [],
+  "author": "",
+  "license": "ISC",
+  "dependencies": {
+    "express": "^4.17.1",
+    "pg": "^8.3.3"
+  },
+  "devDependencies": {},
+  "description": ""
+}
diff --git a/week-3/mandatory/server.js b/week-3/mandatory/server.js
new file mode 100644
index 00000000..09ee61d7
--- /dev/null
+++ b/week-3/mandatory/server.js
@@ -0,0 +1,257 @@
+const express = require("express");
+const app = express();
+const bodyParser = require("body-parser");
+app.use(bodyParser.json());
+
+const { Pool } = require("pg");
+const { request } = require("express");
+
+const db = new Pool({
+  user: "leida",
+  host: "localhost",
+  database: "cyf_ecommerce",
+  password: "******",
+  port: 5432,
+});
+
+app.get("/customers", function (req, res) {
+  db.query(`select * from customers`, function (err, result) {
+    if (err) {
+      res.status(500).json("Could not retrive data from the database.");
+    } else {
+      res.status(200).json(result.rows);
+    }
+  });
+});
+
+app.get("/suppliers", function (req, res) {
+  db.query(`select * from suppliers`, function (err, result) {
+    if (err) {
+      res.status(500).json("Could not retrive data from the database.");
+    } else {
+      res.json(result.rows);
+    }
+  });
+});
+
+//  Return all the product names along with their prices and supplier names.
+
+app.get("/products", function (req, res) {
+  db.query(
+    `select p.product_name, a.unit_price, s.supplier_name
+    from products p join product_availability a on(p.id=a.prod_id) join
+    suppliers s on (a.supp_id=s.id)`,
+    function (err, result) {
+      if (err == undefined) {
+        res.json(result.rows);
+      } else {
+        res.status(500).json("Could not retrive data from the database.");
+      }
+    }
+  );
+});
+
+// list of products by name using a query parameter,This endpoint should still
+// work even if you don't use the `name` query parameter!
+
+app.get("/products/:name", function (req, res) {
+  let prodName = req.params.name;
+
+  db.query(
+    `select p.product_name, a.unit_price, s.supplier_name
+    from products p join product_availability a on(p.id=a.prod_id) join
+    suppliers s on (a.supp_id=s.id) where p.product_name like '%'||$1||'%'`,
+    [prodName],
+    function (err, result) {
+      if (err) {
+        res.status(500).json("Could not retrive data from the database.");
+      } else {
+        res.status(200).json(result.rows);
+      }
+    }
+  );
+  app.get("/customers", function (req, res) {
+    db.query("Select * from customers", (err, result) => {
+      if (err == undefined) {
+        res.json(result.rows);
+      } else {
+        res.status(500).json("Could not retrive data from the database.");
+      }
+    });
+  });
+});
+
+//  Load a single customer by ID.
+
+app.get("/customers/:id", function (req, res) {
+  let custId = Number(req.params.id);
+  db.query("SELECT * FROM customers WHERE id=$1", [custId], (err, result) => {
+    if (err == undefined) {
+      res.status(200).json({ customer: result.rows });
+    } else {
+      console.log(err);
+      res.status(400).json(err);
+    }
+  });
+});
+
+// Add a new POST endpoint `/customers` to create a new customer with name, address, city and country.
+
+app.post("/customers", function (req, res) {
+  const custName = req.body.name;
+  const custAddress = req.body.address;
+  const custCity = req.body.city;
+  const custCountry = req.body.country;
+
+  db.query(
+    "INSERT INTO customers (name, address, city, country) " +
+      "VALUES ($1, $2, $3, $4) " +
+      "RETURNING id",
+    [custName, custAddress, custCity, custCountry],
+    (err) => {
+      if (err == undefined) {
+        res.send("New customer added.");
+      }
+    }
+  );
+});
+
+// Add a new POST endpoint `/products` to create a new product.
+
+app.post("/products", (req, res) => {
+  let newProduct = req.body.product_name;
+
+  const query = "INSERT INTO products (product_name) " + "VALUES($1)";
+  db.query(query, [newProduct], (err) => {
+    if (err == undefined) {
+      res.send("New product is added");
+    } else {
+      res.status(400).send(`An error has occured`);
+    }
+  });
+});
+
+//  create a new order (including an order date, and an order reference) for a customer.
+//  Check that the customerId corresponds to an existing customer or return an error.
+
+app.post("/customers/:customerId/orders", (req, res) => {
+  const customerId = Number(req.params.customerId);
+  const orderDate = req.body.order_date;
+  const orderReference = req.body.order_reference;
+  db.query(
+    "select * from customers where id = $1",
+    [customerId],
+    (err, result) => {
+      if (err == undefined) {
+        if (result.rowCount == 0) {
+          res.send("Customer not found!");
+          return;
+        }
+      }
+    }
+  );
+  db.query(
+    "insert into orders (order_date, order_reference, customer_id)" +
+      "values ($1, $2, $3)",
+    [orderDate, orderReference, customerId],
+    (err) => {
+      if (err == undefined) {
+        res.send("New order added.");
+      }
+    }
+  );
+});
+
+//   Update an existing customer (name, address, city and country).
+
+app.put("/customers/:customerId", (req, res) => {
+  const customerId = Number(req.params.customerId);
+  const name = req.body.name;
+  const address = req.body.address;
+  const city = req.body.city;
+  const country = req.body.country;
+  db.query(
+    "select * from customers where id = $1",
+    [customerId],
+    (err, results) => {
+      if (err == undefined) {
+        if (results.rowCount == 0) {
+          res.send(`No customer with the id of ${customerId} found!`);
+          return;
+        }
+      }
+    }
+  );
+  db.query(
+    "update customers set name = $1, address = $2, city = $3, country = $4" +
+      "where id = $5",
+    [name, address, city, country, customerId],
+    (err) => {
+      if (err == undefined) {
+        res.send("Client details was updated sucessfully!");
+      }
+    }
+  );
+});
+
+//  Add a new DELETE endpoint `/customers/:customerId` to delete an existing
+//  customer only if this customer doesn't have orders.
+
+app.delete("/customers/:customerId", (req, res) => {
+  let customerId = Number(req.params.customerId);
+  db.query(
+    "select * from orders where customer_id = $1",
+    [customerId],
+    (err, result) => {
+      if (err == undefined) {
+        if (result.rowCount > 0) {
+          res.send("There are orders form this customer");
+          return;
+        }
+      }
+    }
+  );
+  db.query(
+    "delete from customers where id = $1",
+    [customerId],
+    (err, results) => {
+      if (err == undefined) {
+        if (results.rowCount == 0) {
+          res.send("We couldn't find this customer");
+        } else {
+          res.send("Customer details has been deleted");
+        }
+      }
+    }
+  );
+});
+
+// Add a new GET endpoint `/customers/:customerId/orders` to load all the orders along with
+// the items in the orders of a specific customer. Especially, the following information should be
+//  returned: order references, order dates, product names, unit prices, suppliers and quantities.
+
+app.get("/customers/:customerId/orders", (req, res) => {
+  const custId = Number(req.params.customerId);
+  let query = `select o.order_reference, o.order_date, p.product_name, a.unit_price, s.supplier_name, i.quantity
+from orders o 
+join order_items i on (o.id = i.order_id)
+join product_availability a on (i.supplier_id = a.supp_id) and
+(i.product_id = a.prod_id)
+join products p on (a.prod_id = p.id)
+join suppliers s on (a.supp_id = s.id)
+where o.customer_id = $1")`;
+  db.query(query, [custId], (err, result) => {
+    if (err == undefined) {
+      if (result.rowCount == 0) {
+        res.status(400).send("No order was found");
+      } else {
+        res.json(result.rows);
+      }
+    }
+  });
+});
+
+const PORT = 3015;
+app.listen(PORT, function () {
+  console.log(`Server is listening on port ${PORT}`);
+});