Refactoring database and model definition into its own file

nodeapp/app.js

@@ -1,38 +1,8 @@
 // Initialize project
+const db = require('./db/db')
 const express = require('express');
-const Sequelize = require('sequelize');
-const Op = Sequelize.Op
 const app = express();
 
-// Setup database, using credentials set in .env
-var sequelize = new Sequelize('database', process.env.DB_USER, process.env.DB_PASS, {
-  dialect: 'sqlite',
-  storage: '.data/database.sqlite'
-});
-var Readings;
-
-// Authenticate with the database
-sequelize.authenticate()
-  .then(function(err) {
-    console.log('Connection has been established successfully.');
-
-    // Define 'readings' table structure
-    Readings = sequelize.define('readings', {
-      timestamp: {
-        type: Sequelize.DATE
-      },
-      reading: {
-        type: Sequelize.INTEGER
-      }
-    });
-
-    // Read data
-    Readings.sync();
-  })
-  .catch(function (err) {
-    console.log('Unable to connect to the database: ', err);
-  });
-
 // Handle requests for the root page by serving the static index.html from the views folder
 app.get("/", function(req, res) {
   res.sendFile(__dirname + "/views/index.html");
@@ -56,11 +26,11 @@ app.get('/getdata', (req, res) => {
     return;
   }
 
-  Readings.findAll({
+  db.Readings.findAll({
     attributes: ['timestamp', 'reading'],
     where: {
       timestamp: {
-        [Op.between]: [new Date(req.query.from), new Date(req.query.to)]
+        [db.Op.between]: [new Date(req.query.from), new Date(req.query.to)]
       }
     },
     order: [
@@ -98,7 +68,7 @@ app.get('/cleanup', (req, res) => {
   Readings.destroy({
     where: {
       timestamp: {
-        [Op.lt]: before
+        [db.Op.lt]: before
       }
     }
   }).then((numRows) => {

nodeapp/db/db.js

@@ -0,0 +1,20 @@
+const Sequelize = require('sequelize');
+const Op = Sequelize.Op
+
+// Setup database, using credentials set in .env
+const sequelize = new Sequelize('database', process.env.DB_USER, process.env.DB_PASS, {
+  dialect: 'sqlite',
+  storage: '.data/database.sqlite'
+});
+
+// Define 'readings' table structure
+const Readings = sequelize.define('readings', {
+  timestamp: {
+    type: Sequelize.DATE
+  },
+  reading: {
+    type: Sequelize.INTEGER
+  }
+});
+
+module.exports = {Op, Readings}

nodeapp/utils/import.js

@@ -1,34 +1,8 @@
-const Sequelize = require('sequelize')
-const Op = Sequelize.Op
+const db = require('../db/db')
 const request = require('request')
 const path = require('path')
 const dotenv = require('dotenv').config({path: path.join(__dirname, '../../.env')})
 
-// Database settings
-const sequelize = new Sequelize('database', process.env.DB_USER, process.env.DB_PASS, {
-  dialect: 'sqlite',
-  storage: '.data/database.sqlite'
-})
-
-sequelize.authenticate().then((err) => {
-  console.log('Connection has been established successfully')
-
-  // Define 'readings' table structure
-  Readings = sequelize.define('readings', {
-    timestamp: {
-      type: Sequelize.DATE
-    },
-    reading: {
-      type: Sequelize.INTEGER
-    }
-  })
-
-  // Read data
-  Readings.sync()
-}).catch((err) => {
-  console.log('Unable to connect to the database: ', err)
-})
-
 // The URL from which to export production data
 const url = 'https://jasonsplant.glitch.me/exportall'
 
@@ -45,8 +19,8 @@ request({
   console.log(body.length + ' items retrieved')
 
   // Remove existing database items
-  Readings.destroy({truncate: true})
+  db.Readings.destroy({truncate: true})
 
   // Add new data to the database
-  Readings.bulkCreate(body)
+  db.Readings.bulkCreate(body)
 });