move from SQLite to MariaDB

.gitignore

@@ -1,3 +1,3 @@
 /node_modules/
-/users.db
 cron_update.log
+.env

db.js

@@ -0,0 +1,11 @@
+const mariadb = require("mariadb");
+
+const pool = mariadb.createPool({
+  host: "10.0.0.1", // "mariadb" if in Docker
+  user: "minecraft_shop_user",
+  password: "UsersBeliev3sNewsp4p3r",
+  database: "minecraft-shop",
+  connectionLimit: 5,
+});
+
+module.exports = pool;

package-lock.json

@@ -11,6 +11,7 @@
       "dependencies": {
         "axios": "^1.13.2",
         "express": "^5.2.1",
+        "mariadb": "^3.4.5",
         "sqlight": "^1.0.0-alpha.8",
         "sqlite3": "^5.1.7",
         "ws": "^8.18.3"
@@ -98,6 +99,21 @@
         "node": ">= 6"
       }
     },
+    "node_modules/@types/geojson": {
+      "version": "7946.0.16",
+      "resolved": "https://registry.npmjs.org/@types/geojson/-/geojson-7946.0.16.tgz",
+      "integrity": "sha512-6C8nqWur3j98U6+lXDfTUWIfgvZU+EumvpHKcYjujKH7woYyLj2sUmff0tRhrqM7BohUw7Pz3ZB1jj2gW9Fvmg==",
+      "license": "MIT"
+    },
+    "node_modules/@types/node": {
+      "version": "24.10.4",
+      "resolved": "https://registry.npmjs.org/@types/node/-/node-24.10.4.tgz",
+      "integrity": "sha512-vnDVpYPMzs4wunl27jHrfmwojOGKya0xyM3sH+UE5iv5uPS6vX7UIoh6m+vQc5LGBq52HBKPIn/zcSZVzeDEZg==",
+      "license": "MIT",
+      "dependencies": {
+        "undici-types": "~7.16.0"
+      }
+    },
     "node_modules/@types/shortid": {
       "version": "0.0.29",
       "resolved": "https://registry.npmjs.org/@types/shortid/-/shortid-0.0.29.tgz",
@@ -554,6 +570,15 @@
       "license": "MIT",
       "optional": true
     },
+    "node_modules/denque": {
+      "version": "2.1.0",
+      "resolved": "https://registry.npmjs.org/denque/-/denque-2.1.0.tgz",
+      "integrity": "sha512-HVQE3AAb/pxF8fQAoiqpvg9i3evqug3hoiwakOyZAwJm+6vZehbkYXZ0l4JxS+I3QxM97v5aaRNhj8v5oBhekw==",
+      "license": "Apache-2.0",
+      "engines": {
+        "node": ">=0.10"
+      }
+    },
     "node_modules/depd": {
       "version": "2.0.0",
       "resolved": "https://registry.npmjs.org/depd/-/depd-2.0.0.tgz",
@@ -1318,6 +1343,40 @@
         "node": ">= 0.6"
       }
     },
+    "node_modules/mariadb": {
+      "version": "3.4.5",
+      "resolved": "https://registry.npmjs.org/mariadb/-/mariadb-3.4.5.tgz",
+      "integrity": "sha512-gThTYkhIS5rRqkVr+Y0cIdzr+GRqJ9sA2Q34e0yzmyhMCwyApf3OKAC1jnF23aSlIOqJuyaUFUcj7O1qZslmmQ==",
+      "license": "LGPL-2.1-or-later",
+      "dependencies": {
+        "@types/geojson": "^7946.0.16",
+        "@types/node": "^24.0.13",
+        "denque": "^2.1.0",
+        "iconv-lite": "^0.6.3",
+        "lru-cache": "^10.4.3"
+      },
+      "engines": {
+        "node": ">= 14"
+      }
+    },
+    "node_modules/mariadb/node_modules/iconv-lite": {
+      "version": "0.6.3",
+      "resolved": "https://registry.npmjs.org/iconv-lite/-/iconv-lite-0.6.3.tgz",
+      "integrity": "sha512-4fCk79wshMdzMp2rH06qWrJE4iolqLhCUH+OiuIgU++RB0+94NlDL81atO7GX55uUKueo0txHNtvEyI6D7WdMw==",
+      "license": "MIT",
+      "dependencies": {
+        "safer-buffer": ">= 2.1.2 < 3.0.0"
+      },
+      "engines": {
+        "node": ">=0.10.0"
+      }
+    },
+    "node_modules/mariadb/node_modules/lru-cache": {
+      "version": "10.4.3",
+      "resolved": "https://registry.npmjs.org/lru-cache/-/lru-cache-10.4.3.tgz",
+      "integrity": "sha512-JNAzZcXrCt42VGLuYz0zfAzDfAvJWW6AfYlDBQyDV5DClI2m5sAmK+OIO7s59XfsRsWHp02jAJrRadPRGTt6SQ==",
+      "license": "ISC"
+    },
     "node_modules/math-intrinsics": {
       "version": "1.1.0",
       "resolved": "https://registry.npmjs.org/math-intrinsics/-/math-intrinsics-1.1.0.tgz",
@@ -2368,6 +2427,12 @@
         "node": ">= 0.6"
       }
     },
+    "node_modules/undici-types": {
+      "version": "7.16.0",
+      "resolved": "https://registry.npmjs.org/undici-types/-/undici-types-7.16.0.tgz",
+      "integrity": "sha512-Zz+aZWSj8LE6zoxD+xrjh4VfkIG8Ya6LvYkZqtUQGJPZjYl53ypCaUwWqo7eI0x66KBGeRo+mlBEkMSeSZ38Nw==",
+      "license": "MIT"
+    },
     "node_modules/unique-filename": {
       "version": "1.1.1",
       "resolved": "https://registry.npmjs.org/unique-filename/-/unique-filename-1.1.1.tgz",

package.json

@@ -14,6 +14,7 @@
   "dependencies": {
     "axios": "^1.13.2",
     "express": "^5.2.1",
+    "mariadb": "^3.4.5",
     "sqlight": "^1.0.0-alpha.8",
     "sqlite3": "^5.1.7",
     "ws": "^8.18.3"

public/js/index.js

@@ -699,7 +699,7 @@ function getCartItemCount(itemId) {
 
 //check if item can be added to cart (if item_stock > cart_item_count)
 async function canAddToCart(itemId) {
-  const item_stock = await getItemStock(itemId);
+  const item_stock = (await getItemStock(itemId)) || 0;
   const cart_item_count = getCartItemCount(itemId);
   return item_stock > cart_item_count;
 }

server.js

@@ -2,7 +2,7 @@ const express = require("express");
 const http = require("http");
 const WebSocket = require("ws");
 const path = require("path");
-const sqlite3 = require("sqlite3").verbose();
+const pool = require("./db");
 
 const app = express();
 const PORT = process.env.PORT || 3100;
@@ -44,38 +44,7 @@ function normalizeItems(arr) {
 const server = http.createServer(app);
 const wss = new WebSocket.Server({ server });
 
-const db = new sqlite3.Database(path.join(__dirname, "users.db"));
-
-// Create table if it doesn't exist
-db.serialize(() => {
-  db.run(`
-    CREATE TABLE IF NOT EXISTS users (
-      username TEXT PRIMARY KEY,
-      password TEXT NOT NULL,
-      balance REAL NOT NULL,
-      adresses TEXT NOT NULL
-    )
-  `);
-
-  db.run(`
-    CREATE TABLE IF NOT EXISTS computers (
-      id INTEGER PRIMARY KEY AUTOINCREMENT,
-      linked_user TEXT,
-      FOREIGN KEY(linked_user) REFERENCES users(username)
-    )
-  `);
-
-  db.run(`
-    CREATE TABLE IF NOT EXISTS shop_items (
-      id INTEGER PRIMARY KEY AUTOINCREMENT,
-      name TEXT UNIQUE NOT NULL,
-      price REAL NOT NULL,
-      enabled INTEGER NOT NULL DEFAULT 1
-    )
-  `);
-});
-
-require("./users-api")(app, wss, db);
+require("./users-api")(app, wss, pool);
 
 // Helper to send JSON to a ws client
 function sendJSON(ws, obj) {

users-api.js

@@ -1,27 +1,13 @@
 /*
   users-api.js
-  User management API endpoints for Express with SQLite.
-
-  Exports a function that takes an Express app instance and sets up:
-    - POST   /api/users           Create a new user
-    - GET    /api/users/:username Get a user by username
-    - PUT    /api/users/:username Update a user's balance and linked computers
-    - GET    /api/users           List all users
-
-  User schema:
-    - username (string, unique)
-    - balance (float)
-    - linked_computers (array of ints, stored as JSON string)
+  User management API endpoints for Express with MariaDB pool.
 */
 
 const express = require("express");
-const path = require("path");
 const axios = require("axios");
 
-// Use a persistent DB file in the project directory
-
-// Helper to parse linked_computers from DB
-function parseLinkedComputers(val) {
+// Helper to parse JSON fields
+function parseJson(val) {
   try {
     const arr = JSON.parse(val);
     return Array.isArray(arr) ? arr : [];
@@ -30,60 +16,72 @@ function parseLinkedComputers(val) {
   }
 }
 
-// Export a function to register routes
-module.exports = function (app, wss, db) {
-  // Helper to get balance from DB
-  function getBalance(username) {
-    const row = db.get("SELECT balance FROM users WHERE username = ?", [
-      username,
-    ]);
-    return row ? row.balance : 0;
+// Export function to register routes
+module.exports = function (app, wss, pool) {
+  // Helper to get balance
+  async function getBalance(username) {
+    const conn = await pool.getConnection();
+    try {
+      const rows = await conn.query(
+        "SELECT balance FROM users WHERE username = ?",
+        [username],
+      );
+      return rows[0]?.balance || 0;
+    } finally {
+      conn.release();
     }
-  // Create user
-  app.post("/api/users", express.json(), (req, res) => {
+  }
+
+  // --- USERS ---
+
+  app.post("/api/users", express.json(), async (req, res) => {
     const { username, password, adresses } = req.body;
     const balance = 1000;
-    let adressesArr = Array.isArray(adresses)
-      ? adresses.filter((a) => typeof a === "string")
-      : [];
     if (typeof username !== "string" || typeof password !== "string") {
       return res.status(400).json({ ok: false, error: "Invalid input" });
     }
-    db.run(
+    const adressesArr = Array.isArray(adresses)
+      ? adresses.filter((a) => typeof a === "string")
+      : [];
+
+    const conn = await pool.getConnection();
+    try {
+      await conn.query(
         "INSERT INTO users (username, password, balance, adresses) VALUES (?, ?, ?, ?)",
         [username, password, balance, JSON.stringify(adressesArr)],
-      function (err) {
-        if (err) return res.status(400).json({ ok: false, error: err.message });
+      );
       res.json({ ok: true });
-      },
-    );
+    } catch (err) {
+      res.status(400).json({ ok: false, error: err.message });
+    } finally {
+      conn.release();
+    }
   });
 
-  // Get user by username
-  app.get("/api/users/:username", (req, res) => {
-    db.get(
-      "SELECT * FROM users WHERE username = ?",
-      [req.params.username],
-      (err, row) => {
-        if (err || !row)
-          return res.status(404).json({ ok: false, error: "User not found" });
-        if (row && typeof row.adresses === "string") {
+  app.get("/api/users/:username", async (req, res) => {
+    const conn = await pool.getConnection();
     try {
-            row.adresses = JSON.parse(row.adresses);
-          } catch {
-            row.adresses = [];
+      const rows = await conn.query("SELECT * FROM users WHERE username = ?", [
+        req.params.username,
+      ]);
+      const user = rows[0];
+      if (!user)
+        return res.status(404).json({ ok: false, error: "User not found" });
+
+      user.adresses = parseJson(user.adresses);
+
+      res.json({ ok: true, user });
+    } catch (err) {
+      res.status(500).json({ ok: false, error: err.message });
+    } finally {
+      conn.release();
     }
-        }
-        res.json({ ok: true, user: row });
-      },
-    );
   });
 
-  // Update user balance
-  app.put("/api/users/:username", express.json(), (req, res) => {
+  app.put("/api/users/:username", express.json(), async (req, res) => {
     const { balance, adresses } = req.body;
-    let updates = [];
-    let params = [];
+    const updates = [];
+    const params = [];
     if (typeof balance === "number") {
       updates.push("balance = ?");
       params.push(balance);
@@ -94,140 +92,165 @@ module.exports = function (app, wss, db) {
         JSON.stringify(adresses.filter((a) => typeof a === "string")),
       );
     }
-    if (updates.length === 0) {
+    if (updates.length === 0)
       return res
         .status(400)
         .json({ ok: false, error: "No valid fields to update" });
-    }
+
     params.push(req.params.username);
-    db.run(
+    const conn = await pool.getConnection();
+    try {
+      const result = await conn.query(
         `UPDATE users SET ${updates.join(", ")} WHERE username = ?`,
         params,
-      function (err) {
-        if (err) return res.status(400).json({ ok: false, error: err.message });
-        if (this.changes === 0)
+      );
+      if (result.affectedRows === 0)
         return res.status(404).json({ ok: false, error: "User not found" });
       res.json({ ok: true });
-      },
-    );
+    } catch (err) {
+      res.status(400).json({ ok: false, error: err.message });
+    } finally {
+      conn.release();
+    }
   });
 
-  // List all users
-  app.get("/api/users", (req, res) => {
-    db.all("SELECT * FROM users", [], (err, rows) => {
-      if (err) return res.status(500).json({ ok: false, error: err.message });
-      rows.forEach((row) => {
-        if (row && typeof row.adresses === "string") {
+  app.get("/api/users", async (req, res) => {
+    const conn = await pool.getConnection();
     try {
-            row.adresses = JSON.parse(row.adresses);
-          } catch {
-            row.adresses = [];
-          }
-        }
+      const rows = await conn.query("SELECT * FROM users");
+      rows.forEach((row) => {
+        row.adresses = parseJson(row.adresses);
       });
       res.json({ ok: true, users: rows });
-    });
+    } catch (err) {
+      res.status(500).json({ ok: false, error: err.message });
+    } finally {
+      conn.release();
+    }
   });
 
-  // Create a new computer and link to user
-  app.post("/api/computers", express.json(), (req, res) => {
+  // --- COMPUTERS ---
+
+  app.post("/api/computers", express.json(), async (req, res) => {
     const { linked_user } = req.body;
-    if (typeof linked_user !== "string") {
+    if (typeof linked_user !== "string")
       return res.status(400).json({ ok: false, error: "Invalid input" });
-    }
-    db.run(
+
+    const conn = await pool.getConnection();
+    try {
+      const result = await conn.query(
         "INSERT INTO computers (linked_user) VALUES (?)",
         [linked_user],
-      function (err) {
-        if (err) return res.status(400).json({ ok: false, error: err.message });
-        res.json({ ok: true, id: this.lastID });
-      },
       );
+      res.json({ ok: true, id: result.insertId });
+    } catch (err) {
+      res.status(400).json({ ok: false, error: err.message });
+    } finally {
+      conn.release();
+    }
   });
 
-  // List all computers, or by user
-  app.get("/api/computers", (req, res) => {
+  app.get("/api/computers", async (req, res) => {
     const user = req.query.user;
     const sql = user
       ? "SELECT * FROM computers WHERE linked_user = ?"
       : "SELECT * FROM computers";
     const params = user ? [user] : [];
-    db.all(sql, params, (err, rows) => {
-      if (err) return res.status(500).json({ ok: false, error: err.message });
+
+    const conn = await pool.getConnection();
+    try {
+      const rows = await conn.query(sql, params);
       res.json({ ok: true, computers: rows });
-    });
+    } catch (err) {
+      res.status(500).json({ ok: false, error: err.message });
+    } finally {
+      conn.release();
+    }
   });
 
-  // Update a computer's linked user
-  app.put("/api/computers/:id", express.json(), (req, res) => {
+  app.put("/api/computers/:id", express.json(), async (req, res) => {
     const { linked_user } = req.body;
-    if (typeof linked_user !== "string") {
+    if (typeof linked_user !== "string")
       return res.status(400).json({ ok: false, error: "Invalid input" });
-    }
-    db.run(
+
+    const conn = await pool.getConnection();
+    try {
+      const result = await conn.query(
         "UPDATE computers SET linked_user = ? WHERE id = ?",
         [linked_user, req.params.id],
-      function (err) {
-        if (err) return res.status(400).json({ ok: false, error: err.message });
-        if (this.changes === 0)
-          return res
-            .status(404)
-            .json({ ok: false, error: "Computer not found" });
-        res.json({ ok: true });
-      },
       );
+      if (result.affectedRows === 0)
+        return res.status(404).json({ ok: false, error: "Computer not found" });
+      res.json({ ok: true });
+    } catch (err) {
+      res.status(400).json({ ok: false, error: err.message });
+    } finally {
+      conn.release();
+    }
   });
 
-  // Get all computers linked to a user
-  app.get("/api/users/:username/computers", (req, res) => {
-    db.all(
+  app.get("/api/users/:username/computers", async (req, res) => {
+    const conn = await pool.getConnection();
+    try {
+      const rows = await conn.query(
         "SELECT * FROM computers WHERE linked_user = ?",
         [req.params.username],
-      (err, rows) => {
-        if (err) return res.status(500).json({ ok: false, error: err.message });
-        res.json({ ok: true, computers: rows });
-      },
       );
+      res.json({ ok: true, computers: rows });
+    } catch (err) {
+      res.status(500).json({ ok: false, error: err.message });
+    } finally {
+      conn.release();
+    }
   });
 
-  // Get the user linked to a computer
-  app.get("/api/computers/:id/user", (req, res) => {
-    db.get(
+  app.get("/api/computers/:id/user", async (req, res) => {
+    const conn = await pool.getConnection();
+    try {
+      const rows = await conn.query(
         "SELECT linked_user FROM computers WHERE id = ?",
         [req.params.id],
-      (err, row) => {
-        if (err || !row)
-          return res
-            .status(404)
-            .json({ ok: false, error: "Computer not found" });
-        res.json({ ok: true, user: row.linked_user });
-      },
       );
+      const user = rows[0]?.linked_user;
+      if (!user)
+        return res.status(404).json({ ok: false, error: "Computer not found" });
+      res.json({ ok: true, user });
+    } catch (err) {
+      res.status(500).json({ ok: false, error: err.message });
+    } finally {
+      conn.release();
+    }
   });
-  // --- SHOP ITEMS API ---
 
-  // Get all enabled items (for homepage)
-  app.get("/api/shop/items", (req, res) => {
-    db.all(
+  // --- SHOP ITEMS ---
+
+  app.get("/api/shop/items", async (req, res) => {
+    const conn = await pool.getConnection();
+    try {
+      const rows = await conn.query(
         "SELECT id, name, price, quantity FROM shop_items WHERE enabled = 1",
-      [],
-      (err, rows) => {
-        if (err) return res.status(500).json({ ok: false, error: err.message });
-        res.json({ ok: true, items: rows });
-      },
       );
-  });
-
-  // Get all items (admin)
-  app.get("/api/shop/items/all", (req, res) => {
-    db.all("SELECT * FROM shop_items", [], (err, rows) => {
-      if (err) return res.status(500).json({ ok: false, error: err.message });
       res.json({ ok: true, items: rows });
-    });
+    } catch (err) {
+      res.status(500).json({ ok: false, error: err.message });
+    } finally {
+      conn.release();
+    }
   });
 
-  // Add a new item (admin)
-  app.post("/api/shop/items", express.json(), (req, res) => {
+  app.get("/api/shop/items/all", async (req, res) => {
+    const conn = await pool.getConnection();
+    try {
+      const rows = await conn.query("SELECT * FROM shop_items");
+      res.json({ ok: true, items: rows });
+    } catch (err) {
+      res.status(500).json({ ok: false, error: err.message });
+    } finally {
+      conn.release();
+    }
+  });
+
+  app.post("/api/shop/items", express.json(), async (req, res) => {
     const { name, price, enabled, quantity } = req.body;
     if (
       typeof name !== "string" ||
@@ -236,18 +259,21 @@ module.exports = function (app, wss, db) {
     ) {
       return res.status(400).json({ ok: false, error: "Invalid input" });
     }
-    db.run(
+    const conn = await pool.getConnection();
+    try {
+      const result = await conn.query(
         "INSERT INTO shop_items (name, price, enabled, quantity) VALUES (?, ?, ?, ?)",
-      [name, price, enabled === 0 ? 0 : 1, quantity],
-      function (err) {
-        if (err) return res.status(400).json({ ok: false, error: err.message });
-        res.json({ ok: true, id: this.lastID });
-      },
+        [name, price, enabled ? 1 : 0, quantity],
       );
+      res.json({ ok: true, id: result.insertId });
+    } catch (err) {
+      res.status(400).json({ ok: false, error: err.message });
+    } finally {
+      conn.release();
+    }
   });
 
-  // Update an item (admin)
-  app.put("/api/shop/items/:id", express.json(), (req, res) => {
+  app.put("/api/shop/items/:id", express.json(), async (req, res) => {
     const { name, price, enabled, quantity } = req.body;
     const updates = [];
     const params = [];
@@ -267,123 +293,108 @@ module.exports = function (app, wss, db) {
       updates.push("quantity = ?");
       params.push(quantity);
     }
-    if (updates.length === 0) {
+    if (updates.length === 0)
       return res
         .status(400)
         .json({ ok: false, error: "No valid fields to update" });
-    }
     params.push(req.params.id);
-    db.run(
+
+    const conn = await pool.getConnection();
+    try {
+      const result = await conn.query(
         `UPDATE shop_items SET ${updates.join(", ")} WHERE id = ?`,
         params,
-      function (err) {
-        if (err) return res.status(400).json({ ok: false, error: err.message });
-        if (this.changes === 0)
+      );
+      if (result.affectedRows === 0)
         return res.status(404).json({ ok: false, error: "Item not found" });
       res.json({ ok: true });
-      },
-    );
+    } catch (err) {
+      res.status(400).json({ ok: false, error: err.message });
+    } finally {
+      conn.release();
+    }
   });
 
-  // Delete an item (admin)
-  app.delete("/api/shop/items/:id", (req, res) => {
-    db.run(
-      "DELETE FROM shop_items WHERE id = ?",
-      [req.params.id],
-      function (err) {
-        if (err) return res.status(400).json({ ok: false, error: err.message });
-        if (this.changes === 0)
+  app.delete("/api/shop/items/:id", async (req, res) => {
+    const conn = await pool.getConnection();
+    try {
+      const result = await conn.query("DELETE FROM shop_items WHERE id = ?", [
+        req.params.id,
+      ]);
+      if (result.affectedRows === 0)
         return res.status(404).json({ ok: false, error: "Item not found" });
       res.json({ ok: true });
-      },
-    );
+    } catch (err) {
+      res.status(400).json({ ok: false, error: err.message });
+    } finally {
+      conn.release();
+    }
   });
 
+  // --- SHOP BUY & USER TRANSFER ---
+
   app.post("/api/shop/items/buy", async (req, res) => {
     const { userId, addressId, items } = req.body;
-
     if (!userId || !addressId || !Array.isArray(items)) {
-      return res.status(400).json({
-        ok: false,
-        error: "Missing or invalid parameters",
-      });
-    }
-
-    function getPrice(db, itemId) {
-      return new Promise((resolve, reject) => {
-        db.get(
-          "SELECT price FROM shop_items WHERE name = ?",
-          [itemId],
-          (err, row) => {
-            if (err) return reject({ status: 400, message: err.message });
-            if (!row) return reject({ status: 404, message: "Item not found" });
-
-            resolve(row.price);
-          },
-        );
-      });
-    }
-
-    function getBalance(db, username) {
-      return new Promise((resolve, reject) => {
-        db.get(
-          "SELECT balance FROM users WHERE username = ?",
-          [username],
-          (err, row) => {
-            if (err) return reject({ status: 400, message: err.message });
-            if (!row) return reject({ status: 404, message: "User not found" });
-
-            resolve(row.balance);
-          },
-        );
-      });
+      return res
+        .status(400)
+        .json({ ok: false, error: "Missing or invalid parameters" });
     }
 
+    const conn = await pool.getConnection();
     try {
-      var shopList = {};
-      var total = 0;
+      await conn.beginTransaction();
+
+      let total = 0;
+      const shopList = {};
+
       for (const item of items) {
-        if (!item.id || !item.quantity) {
-          return res.status(400).json({
-            ok: false,
-            error: "Invalid item format",
-          });
-        }
+        if (!item.id || !item.quantity)
+          return res
+            .status(400)
+            .json({ ok: false, error: "Invalid item format" });
 
         const response = await axios.get(
           `http://localhost:3100/api/item/${item.id}`,
         );
         const stockCount = response.data.item.count;
+        if (stockCount < item.quantity)
+          return res
+            .status(400)
+            .json({ ok: false, error: `Not enough stock for item ${item.id}` });
 
-        if (stockCount < item.quantity) {
-          return res.status(400).json({
-            ok: false,
-            error: `Not enough stock for item ${item.id}`,
-          });
-        }
-        const price = await getPrice(db, item.id);
-        const balance = await getBalance(db, userId);
-        if (balance < price * item.quantity) {
-          return res.status(400).json({
+        const [priceRow] = await conn.query(
+          "SELECT price FROM shop_items WHERE name = ?",
+          [item.id],
+        );
+        if (!priceRow)
+          return res
+            .status(404)
+            .json({ ok: false, error: `Item not found ${item.id}` });
+        const price = priceRow.price;
+
+        const [userRow] = await conn.query(
+          "SELECT balance FROM users WHERE username = ?",
+          [userId],
+        );
+        if (!userRow)
+          return res.status(404).json({ ok: false, error: "User not found" });
+        if (userRow.balance < price * item.quantity)
+          return res
+            .status(400)
+            .json({
               ok: false,
               error: `Insufficient balance for item ${item.id}`,
             });
-        }
+
         const shopId = response.data.shopId;
-        if (!shopList[shopId]) {
-          shopList[shopId] = [];
-        }
-        shopList[shopId].push({
-          id: item.id,
-          count: item.quantity,
-        });
+        if (!shopList[shopId]) shopList[shopId] = [];
+        shopList[shopId].push({ id: item.id, count: item.quantity });
         total += price * item.quantity;
       }
-      console.log("Shoplist");
-      console.log(shopList);
+
+      // Send via WebSocket
       Object.keys(shopList).forEach((shop) => {
-        console.log("Shop");
-        console.log(shop);
         const request = {
           type: "request",
           address: addressId,
@@ -391,101 +402,78 @@ module.exports = function (app, wss, db) {
           items: shopList[shop],
         };
         wss.clients.forEach((client) => {
-          if (client.readyState === 1) {
-            client.send(JSON.stringify(request));
-          }
+          if (client.readyState === 1) client.send(JSON.stringify(request));
         });
       });
-      // remove total from db
-      db.run(
-        `UPDATE users SET balance = balance - ? WHERE username = ?`,
+
+      // Deduct total from user
+      await conn.query(
+        "UPDATE users SET balance = balance - ? WHERE username = ?",
         [total, userId],
-        (err) => {
-          if (err) {
-            console.error(err);
-            return res.status(500).json({
-              ok: false,
-              error: "Internal server error",
-            });
-          }
-        },
       );
-      // add total to 'ZareMate'
-      db.run(
-        `UPDATE users SET balance = balance + ? WHERE username = 'ZareMate'`,
+      // Add total to 'ZareMate'
+      await conn.query(
+        "UPDATE users SET balance = balance + ? WHERE username = 'ZareMate'",
         [total],
-        (err) => {
-          if (err) {
-            console.error(err);
-            return res.status(500).json({
-              ok: false,
-              error: "Internal server error",
-            });
-          }
-        },
       );
-      res.status(200).json({
+
+      await conn.commit();
+      res
+        .status(200)
+        .json({
           ok: true,
           message: `Successfully purchased items for user ${userId} at ${total}`,
         });
     } catch (err) {
+      await conn.rollback();
       console.error(err);
-      return res.status(500).json({
-        ok: false,
-        error: "Internal server error",
-      });
+      res.status(500).json({ ok: false, error: "Internal server error" });
+    } finally {
+      conn.release();
     }
   });
-  app.post("/api/users/transfer", (req, res) => {
+
+  app.post("/api/users/transfer", async (req, res) => {
     const { from, to, amount } = req.body;
-    if (!from || !to || !amount) {
-      return res.status(400).json({
-        ok: false,
-        error: "Missing required fields",
-      });
-    }
-    if (amount <= 0) {
-      return res.status(400).json({
-        ok: false,
-        error: "Invalid amount",
-      });
-    }
-    const balance = getBalance(from);
-    if (amount > balance) {
-      return res.status(400).json({
-        ok: false,
-        error: "Insufficient balance",
-      });
-    }
-    db.run(
-      `UPDATE users SET balance = balance - ? WHERE username = ?`,
+    if (!from || !to || !amount || amount <= 0)
+      return res.status(400).json({ ok: false, error: "Invalid input" });
+
+    const conn = await pool.getConnection();
+    try {
+      await conn.beginTransaction();
+      const [fromRow] = await conn.query(
+        "SELECT balance FROM users WHERE username = ?",
+        [from],
+      );
+      if (!fromRow)
+        return res.status(404).json({ ok: false, error: "Sender not found" });
+      if (fromRow.balance < amount)
+        return res
+          .status(400)
+          .json({ ok: false, error: "Insufficient balance" });
+
+      await conn.query(
+        "UPDATE users SET balance = balance - ? WHERE username = ?",
         [amount, from],
-      (err) => {
-        if (err) {
-          console.error(err);
-          return res.status(500).json({
-            ok: false,
-            error: "Internal server error",
-          });
-        }
-      },
       );
-    db.run(
-      `UPDATE users SET balance = balance + ? WHERE username = ?`,
+      await conn.query(
+        "UPDATE users SET balance = balance + ? WHERE username = ?",
         [amount, to],
-      (err) => {
-        if (err) {
-          console.error(err);
-          return res.status(500).json({
-            ok: false,
-            error: "Internal server error",
-          });
-        }
-      },
       );
-    res.status(200).json({
+
+      await conn.commit();
+      res
+        .status(200)
+        .json({
           ok: true,
           message: `Successfully transferred ${amount} from ${from} to ${to}`,
         });
+    } catch (err) {
+      await conn.rollback();
+      console.error(err);
+      res.status(500).json({ ok: false, error: "Internal server error" });
+    } finally {
+      conn.release();
+    }
   });
 };