npm install sql.js --save

const{app,BrowserWindow}=require("electron");

let win;
function onLoad()
{
  win=new BrowserWindow({
    width:800,
    height:600
  });
  win.loadURL(`file://${__dirname}/index.html`);
}

app.on("ready",onLoad());

var path=require("path");
path.exists('filepath",(status)=>
{
....
});
var status=path.existsSync("file");
//===============================
var fs=require("fs");
fs.exists('filepath",(status)=>
{
....
});
var status=path.existsSync("file");

fs.stat('foo.txt', function(err, stat) {
    if(err == null) {
        console.log('فایل موجوده');
    } else if(err.code == 'ENOENT') {
        // فایل وجود نداره
        fs.writeFile('log.txt', 'Some log\n');
    } else {
        //خطای دیگری رخ داده است
    }
});

try {
  stats = fs.statSync(path);
  console.log("File exists.");
}
catch (e) {
  console.log("File does not exist.");
}

const fs = require('fs');
const sql = require('sql.js');

  dbPath = './mydb.sqlite';
  dbExists=false;

try {
  dbExists = fs.statSync(dbPath);
}
catch (e) {
}

if(!dbExists)
{
  //create Database
var sqlStr=fs.readFileSync("./sql.txt");
var db = new sql.Database();
db.run(String(sqlStr));

//write to disk
var data=db.export();
var buffer=new Buffer(data);
fs.writeFileSync(dbPath,buffer);
}
else{
  var buffer = fs.readFileSync(dbPath);
  var db = new sql.Database(buffer);
}

CREATE TABLE numbers (
    id     INT          PRIMARY KEY
                        UNIQUE
                        NOT NULL,
    fname  VARCHAR (20) NOT NULL,
    lname  VARCHAR (30) NOT NULL,
    number VARCHAR (15) NOT NULL
);
insert into numbers values(1,'ali','yeganeh','03111223344');
insert into numbers values(2,'xxx','yyy','45454555');

global.db=db;

app.on('window-all-closed', () => {
  db.close();
  if (process.platform !== 'darwin') {
    app.quit();
  }
});