DatabaseIntigration.txt

var options = {
  host: process.env.DATABASEHOST, 
  port: process.env.DATABASEPORT,    
  user: process.env.DATABASEUSER,   
  password: process.env.DATABASEPASSWORD, 
  database: process.env.DATABASENAME,
};
var db;
connectToDB = function () {
  db = mysql.createConnection(options);
  db.connect(function(err) {
    if (err) {
      setTimeout(connectToDB, 2000);
    }
  });
  db.on('error', function(err) {
    //Error message
    systemMessage("Error: " + err);
    if(err.code === 'PROTOCOL_CONNECTION_LOST') { // Connection to the MySQL server is usually
      connectToDB();                         // lost due to either server restart, or a
    } else {                                      // connnection idle timeout (the wait_timeout
      throw err;                                  // server variable configures this)
    }
  });

};

systemMessage = function(message) {
  console.log("====================================================");
  console.log("Database is Reconnecting But the app will not crash");
  console.log("====================================================");
};

connectToDB();
console.log("Application is Running");





app.post("/formdata", (req, res) => {
    let stud_name = req.body.stud_name.toString();
    let stud_dob = req.body.stud_dob.toString();
    let stud_wp_num = req.body.stud_wp_num.toString();
    let stud_email = req.body.stud_email.toString();
    let stud_department = req.body.stud_department.toString();
    let stud_year = req.body.stud_year.toString();
    db.query("select stud_email from form_data where stud_email = ?", [stud_email], (err, data) => {
        if(err){
            console.log(err);
        }
        if(data.length == 0){
            db.query("insert into form_data (stud_name, stud_dob, stud_wp_num, stud_email, stud_department, stud_year) values (?, ?, ?, ?, ?, ?)",
            [stud_name,stud_dob,stud_wp_num,stud_email,stud_department,stud_year],
            (err, data) => {
                if (err){
                    console.log(err);
                }
                var msg = "Thank You "+stud_name+" for registering for Developer's Hunt 2021 Here is Our Whatsapp group Join It for further Updates "+ wp_link;
                var mailOptions = {
                  from: process.env.EMAIL,
                  to: stud_email,
                  subject: 'Email From GRCS DEVELOPERS CLUB',
                  text: msg
                };
                transporter.sendMail(mailOptions, function(error, info){
                if (error) {
                  console.log(error);
                } else {
                  console.log('Email sent: ' + info.response);
                }
              });
              req.session.message = {
                type: "success",
                message: 'Thank You '+stud_name+' successfully regestered Please Check your mailbox for Whatsaap group link'
              }
              res.redirect("/")
            });
        }else {
            req.session.message = {
                type: "danger",
                message: 'Email already exists ! Try with different Email Id'
              }
              res.redirect("/")
        }
    });

});