var mySql = require("mysql");

var connection = mySql.createConnection({
  host : "localhost",
  user : "root",
  password : "rahul",
  database : "testDb" //schema
});

connection.connect();

connection.query("select * from departmentTbl",function(err,rows,fields){

  if(err){
    console.log(err.stack);
  }

  for(var i = 0; i < rows.length; i++){
    console.log("DepartmentId : '"+rows[i]["deptId"]+"', DepartmentName '"+rows[i]["deptName"]+"'");
  }
});

connection.end();

var Promise = require("promise");

var mySql = require("mysql");

var connection = mySql.createConnection({
  host : "localhost",
  user : "root",
  password : "rahul",
  database : "testDb" //schema
});

var p  = Promise.resolve(connection.connect());


var sqlQuery = p.then(function(con){
  return Promise.resolve(con.query);
});

sqlQuery.then(function(q){

 q("select * from departmentTbl").then(function(err,row,fields){
   if(err){
    console.log(err.stack);
   }

   for(var i = 0; i < rows.length; i++){
    console.log("DepartmentId : '"+rows[i]["deptId"]+"', DepartmentName '"+rows[i]["deptName"]+"'");
   };

  }).done(function(){
    connection.end();
 });
});