text: var mysql = require('mysql');
  exports.pool = mysql.createPool({
    host  : 'localhost',
    user  : 'student',
    password: 'default',
    database: 'student'
  });
  // exports.getConnection = function(callback) {
  //   pool.getConnection(function(err, connection) {
  //     callback(err, connection);
  //   });
  // };