NW5 Manchester - Mohammed Alhallaq SQL WEEK 03

2-api/.gitignore

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+node_modules/

2-api/dbConnection.js

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+const { Pool } = require("pg");
+
+const pool = new Pool({
+  user: "postgres",
+  password: "cyf",
+  host: "localhost",
+  port: 5432,
+  database: "cyf_ecommerce",
+});
+
+module.exports = pool;

2-api/package.json

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+{
+  "name": "cyf-ecommerce-api",
+  "version": "1.0.0",
+  "main": "server.js",
+  "author": "Mohammed",
+  "license": "MIT",
+  "dependencies": {
+    "express": "^4.18.2",
+    "pg": "^8.9.0"
+  },
+  "devDependencies": {
+    "nodemon": "^2.0.20"
+  },
+  "scripts": {
+    "start": "nodemon server.js"
+  }
+}

2-api/server.js

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+const express = require("express");
+const pool = require("./dbConnection");
+
+const app = express();
+
+app.use(express.json());
+
+// Get All customers End Point
+app.get("/customers", async (req, res) => {
+  try {
+    const result = await pool.query("SELECT * FROM customers");
+    res.json(result.rows);
+  } catch (err) {
+    console.error(err);
+    res.status(500).json({ error: "Internal Server Error" });
+  }
+});
+
+// Get customer by ID API end point
+
+app.get("/customers/:customerId", async (req, res) => {
+  try {
+    const { customerId } = req.params;
+    const query = "SELECT * FROM customers WHERE id = $1";
+    const result = await pool.query(query, [customerId]);
+    if (result.rowCount === 0) {
+      res
+        .status(404)
+        .json({ error: `No customer with ID ${customerId} found` });
+    } else {
+      res.json(result.rows[0]);
+    }
+  } catch (error) {
+    console.error(error);
+    res.status(500).json({ error: "Something went wrong!" });
+  }
+});
+
+//Get All Products or a specific product name End Point
+
+app.get("/products", async (req, res) => {
+  try {
+    const { name } = req.query;
+    let query = `
+        SELECT products.product_name, product_availability.unit_price, suppliers.supplier_name
+        FROM products
+        JOIN product_availability ON products.id = product_availability.prod_id
+        JOIN suppliers ON suppliers.id = product_availability.supp_id
+        WHERE ($1::text IS NULL OR products.product_name ILIKE $1)
+        `;
+    const values = [name ? `%${name}%` : null];
+    const result = await pool.query(query, values);
+    res.json(result.rows);
+  } catch (error) {
+    console.error(error);
+    res.status(500).json({ error: "Something went wrong!" });
+  }
+});
+
+// POST customer API End point
+app.post("/customers", async (req, res) => {
+  try {
+    const { name, address, city, country } = req.body;
+    const query = `
+        INSERT INTO customers (name, address, city, country)
+        VALUES ($1, $2, $3, $4)
+        RETURNING *
+      `;
+    const result = await pool.query(query, [name, address, city, country]);
+    res.status(201).json(result.rows[0]);
+  } catch (error) {
+    console.error(error);
+    res.status(500).json({ error: "Something went wrong!" });
+  }
+});
+
+// POST product API End point
+app.post("/products", async (req, res) => {
+  try {
+    const { product_name } = req.body;
+    const query = `
+        INSERT INTO products (product_name)
+        VALUES ($1)
+        RETURNING *
+      `;
+    const result = await pool.query(query, [product_name]);
+    res.status(201).json(result.rows[0]);
+  } catch (error) {
+    console.error(error);
+    res.status(500).json({ error: "Something went wrong!" });
+  }
+});
+
+//POST Customer order End point
+
+app.post("/customers/:customerId/orders", async (req, res) => {
+  const customerId = req.params.customerId;
+  const { order_date, order_reference } = req.body;
+
+  try {
+    // Check if customer exists
+    const customer = await pool.query("SELECT * FROM customers WHERE id = $1", [
+      customerId,
+    ]);
+    if (customer.rows.length === 0) {
+      return res.status(404).json({ error: "Customer not found." });
+    }
+
+    // Insert new order
+    const query = `
+        INSERT INTO orders (order_date, order_reference, customer_id)
+        VALUES ($1, $2, $3)
+        RETURNING *
+      `;
+    const result = await pool.query(query, [
+      order_date,
+      order_reference,
+      customerId,
+    ]);
+    res.status(201).json(result.rows[0]);
+  } catch (error) {
+    console.error(error);
+    res.status(500).json({ error: "Something went wrong!" });
+  }
+});
+
+// PUT API end point to update Customer Details
+
+app.put("/customers/:customerId", async (req, res) => {
+  const customerId = req.params.customerId;
+  const { name, address, city, country } = req.body;
+
+  try {
+    // Check if customer exists
+    const customer = await pool.query("SELECT * FROM customers WHERE id = $1", [
+      customerId,
+    ]);
+    if (customer.rows.length === 0) {
+      return res.status(404).json({ error: "Customer not found." });
+    }
+
+    // Update customer
+    const query = `
+        UPDATE customers
+        SET name = $1, address = $2, city = $3, country = $4
+        WHERE id = $5
+        RETURNING *
+      `;
+    const result = await pool.query(query, [
+      name,
+      address,
+      city,
+      country,
+      customerId,
+    ]);
+    res.json(result.rows[0]);
+  } catch (error) {
+    console.error(error);
+    res.status(500).json({ error: "Something went wrong!" });
+  }
+});
+
+// DELETE API end point to delete the order and its details
+
+app.delete("/orders/:orderId", async (req, res) => {
+  const orderId = req.params.orderId;
+  try {
+    // Get order items associated with the order
+    const orderItems = await pool.query(
+      "SELECT * FROM order_items WHERE order_id = $1",
+      [orderId]
+    );
+    const orderItemIds = orderItems.rows.map((item) => item.id);
+
+    // Delete the order and associated order items in a transaction
+    await pool.query("BEGIN");
+    await pool.query("DELETE FROM order_items WHERE id = ANY($1)", [
+      orderItemIds,
+    ]);
+    await pool.query("DELETE FROM orders WHERE id = $1", [orderId]);
+    await pool.query("COMMIT");
+
+    res.status(200).json({
+      message: "Order and associated order items deleted successfully.",
+    });
+  } catch (error) {
+    await pool.query("ROLLBACK");
+    console.error(error);
+    res.status(500).json({ error: "Something went wrong!" });
+  }
+});
+
+// DELETE API end point to delete customers without orders
+
+app.delete("/customers/:customerId", async (req, res) => {
+  const customerId = req.params.customerId;
+  try {
+    // Check if customer has associated orders
+    const orders = await pool.query(
+      "SELECT * FROM orders WHERE customer_id = $1",
+      [customerId]
+    );
+    if (orders.rows.length > 0) {
+      return res.status(400).json({
+        error: "Customer has associated orders and cannot be deleted.",
+      });
+    }
+
+    // Delete the customer
+    await pool.query("DELETE FROM customers WHERE id = $1", [customerId]);
+
+    res.status(200).json({ message: "Customer deleted successfully." });
+  } catch (error) {
+    console.error(error);
+    res.status(500).json({ error: "Something went wrong!" });
+  }
+});
+
+// GET API point to send customer order information
+
+app.get("/customers/:customerId/orders", async (req, res) => {
+  const customerId = req.params.customerId;
+  try {
+    const orders = await pool.query(
+      "SELECT * FROM orders WHERE customer_id = $1",
+      [customerId]
+    );
+    const result = [];
+    for (const order of orders.rows) {
+      const orderItem = await pool.query(
+        `SELECT oi.order_id, oi.quantity, pa.unit_price, p.product_name, s.supplier_name 
+        FROM order_items oi
+        JOIN product_availability pa ON oi.product_id = pa.prod_id AND oi.supplier_id = pa.supp_id
+        JOIN products p ON oi.product_id = p.id
+        JOIN suppliers s ON oi.supplier_id = s.id
+        WHERE oi.order_id = $1`,
+        [order.id]
+      );
+      result.push({
+        order_reference: order.order_reference,
+        order_date: order.order_date,
+        items: orderItem.rows,
+      });
+    }
+    res.status(200).json(result);
+  } catch (error) {
+    console.error(error);
+    res.status(500).json({ error: "Something went wrong!" });
+  }
+});
+
+app.listen(3000, () => {
+  console.log("Server is listening on port 3000");
+});