If you are getting the error cannot find node module sqlite3 or please install sqlite3 package manually in electron application after install sqlite. Then this solution can be help full to fix your issue.

Step 1: We need to clone electron quick start project on your local

Source: https://electronjs.org/docs/tutorial/first-app

$ git clone https://github.com/electron/electron-quick-start

Step 2: Go into the repository

$ cd electron-quick-start

Step 3: Install electronJs dependencies

$ npm install

Step 4: Run electron project

$ npm start

Now lets come to most challenging part

Step 5: Now we need to install sqlite dependency

$ npm install sqlite3 --save
$ npm install sequelize --save

Step 6: Open main.js in your IDE and add this code at the end of file to create database connection

Source: http://docs.sequelizejs.com/manual/installation/usage.html

// Create database connection
const Sequelize = require('sequelize');
    const sequelize = new Sequelize('database', 'username', 'password', {
    host: 'localhost',
    dialect: 'sqlite',
    operatorsAliases: false,
    pool: {
        max: 5,
        min: 0,
        acquire: 30000,
        idle: 10000
    },
    storage: './database.sqlite'
});

// Test connection
sequelize
    .authenticate()
    .then(() => {
        console.log('Connection has been established successfully.');
    })
    .catch(err => {
        console.error('Unable to connect to the database:', err);
    });

Step 7: Now again start your electron project using npm start and you will start getting exception

Error: Please install sqlite3 package manually

How we can fix it?

Step 8: To fix this error we need to install electron-rebuild package. Make sure you are using cmd run as Administrator before execute this command otherwise it will never work.

$ npm install --save-dev electron-rebuild

Step 9: Now we have to configure the rebuild command in package.json under the script

"scripts": {
    "rebuild": "electron-rebuild -f -w sqlite3"
}

Step 10: Now we Need to install python and set it into Path in environment variable.

Download Python: https://www.python.org/download/releases/2.7/
Open Control Panel > System and Security > System > Advanced System Setting > Enviroment Variables
Under User variables for %username% section click on new to add a new Item
Set variable name Path and variable value C:\Python27 (where you have installed python) and click on OK Button

Step 10: Now open a new command line and rebuild your electron project

$ npm run rebuild

Step 11: And now you can run it and it will works fine

$ npm start

Happy Programming.

NOTE: If you will get this error on Step 10 while running npm run rebuild

× Rebuild Failed

An unhandled error occurred inside electron-rebuild
Building the projects in this solution one at a time. To enable parallel build, please add the "/m" switch.
MSBUILD : error MSB3428: Could not load the Visual C++ component "VCBuild.exe". To fix this, 1) install the .NET Framework 2.0 SDK, 2) install Microsoft Visual Studio 2005 or 3) add the location of the component to the system path if it is installed elsewhere.  [C:\Projects\Test\node_modules\sqlite3\build\binding.sln]
gyp ERR! build error
gyp ERR! stack Error: `C:\Windows\Microsoft.NET\Framework\v4.0.30319\msbuild.exe` failed with exit code: 1
gyp ERR! stack     at ChildProcess.onExit (C:\Projects\Test\node_modules\node-gyp\lib\build.js:262:23)
gyp ERR! stack     at emitTwo (events.js:106:13)
gyp ERR! stack     at ChildProcess.emit (events.js:191:7)
gyp ERR! stack     at Process.ChildProcess._handle.onexit (internal/child_process.js:215:12)
gyp ERR! System Windows_NT 10.0.17134
gyp ERR! command "C:\\Program Files\\nodejs\\node.exe" "C:\\Projects\\Test\\node_modules\\node-gyp\\bin\\node-gyp.js" "rebuild" "--target=1.8.8" "--arch=x64" "--dist-url=https://atom.io/download/electron" "--build-from-source" "--module_name=node_sqlite3" "--module_path=C:\\Projects\\Test\\node_modules\\sqlite3\\lib\\binding\\electron-v1.8-win32-x64" "--host=https://mapbox-node-binary.s3.amazonaws.com" "--remote_path=./{name}/v4.0.2/{toolset}/" "--package_name=electron-v1.8-win32-x64.tar.gz"
gyp ERR! cwd C:\\Projects\\Test\node_modules\sqlite3
gyp ERR! node -v v6.9.5
gyp ERR! node-gyp -v v3.8.0
gyp ERR! not ok

Failed with exit code: 1

Error: Building the projects in this solution one at a time. To enable parallel build, please add the "/m" switch.
MSBUILD : error MSB3428: Could not load the Visual C++ component "VCBuild.exe". To fix this, 1) install the .NET Framework 2.0 SDK, 2) install Microsoft Visual Studio 2005 or 3) add the location of the component to the system path if it is installed elsewhere.  [C:\Projects\Test\node_modules\sqlite3\build\binding.sln]
gyp ERR! build error
gyp ERR! stack Error: `C:\Windows\Microsoft.NET\Framework\v4.0.30319\msbuild.exe` failed with exit code: 1
gyp ERR! stack     at ChildProcess.onExit (C:\Projects\Test\node_modules\node-gyp\lib\build.js:262:23)
gyp ERR! stack     at emitTwo (events.js:106:13)
gyp ERR! stack     at ChildProcess.emit (events.js:191:7)
gyp ERR! stack     at Process.ChildProcess._handle.onexit (internal/child_process.js:215:12)
gyp ERR! System Windows_NT 10.0.17134
gyp ERR! command "C:\\Program Files\\nodejs\\node.exe" "C:\\Projects\\Test\\node_modules\\node-gyp\\bin\\node-gyp.js" "rebuild" "--target=1.8.8" "--arch=x64" "--dist-url=https://atom.io/download/electron" "--build-from-source" "--module_name=node_sqlite3" "--module_path=C:\\Projects\\Test\\node_modules\\sqlite3\\lib\\binding\\electron-v1.8-win32-x64" "--host=https://mapbox-node-binary.s3.amazonaws.com" "--remote_path=./{name}/v4.0.2/{toolset}/" "--package_name=electron-v1.8-win32-x64.tar.gz"
gyp ERR! cwd C:\\Projects\\Test\node_modules\sqlite3
gyp ERR! node -v v6.9.5
gyp ERR! node-gyp -v v3.8.0
gyp ERR! not ok

Failed with exit code: 1
    at SafeSubscriber._error (C:\Projects\Test\node_modules\spawn-rx\lib\src\index.js:277:84)
    at SafeSubscriber.__tryOrUnsub (C:\Projects\Test\node_modules\rxjs\Subscriber.js:242:16)
    at SafeSubscriber.error (C:\Projects\Test\node_modules\rxjs\Subscriber.js:201:26)
    at Subscriber._error (C:\Projects\Test\node_modules\rxjs\Subscriber.js:132:26)
    at Subscriber.error (C:\Projects\Test\node_modules\rxjs\Subscriber.js:106:18)
    at MapSubscriber.Subscriber._error (C:\Projects\Test\node_modules\rxjs\Subscriber.js:132:26)
    at MapSubscriber.Subscriber.error (C:\Projects\Test\node_modules\rxjs\Subscriber.js:106:18)
    at SafeSubscriber._next (C:\Projects\Test\node_modules\spawn-rx\lib\src\index.js:251:65)
    at SafeSubscriber.__tryOrSetError (C:\Projects\Test\node_modules\rxjs\Subscriber.js:251:16)
    at SafeSubscriber.next (C:\Projects\Test\node_modules\rxjs\Subscriber.js:191:27)

Then execute this in command line npm install windows-build-tools --global

And while installing windows-build-tools if you will get this exception

async function aquireInstallers(cb) {
      ^^^^^^^^
SyntaxError: Unexpected token function
    at Object.exports.runInThisContext (vm.js:76:16)
    at Module._compile (module.js:542:28)
    at Object.Module._extensions..js (module.js:579:10)
    at Module.load (module.js:487:32)
    at tryModuleLoad (module.js:446:12)
    at Function.Module._load (module.js:438:3)
    at Module.require (module.js:497:17)
    at require (internal/module.js:20:19)
    at Object.<anonymous> (C:\Users\User\AppData\Roaming\npm\node_modules\windows-build-tools\dist\start.js:4:29)

It means you are using old version of nodeJS to fix it you can install old version of windows-build-tools using npm install windows-build-tools@2.2.1 --global

And now you can start the project using npm start

ElectronJs: please install sqlite3 package manually

How we can fix it?