Connect to database

const queries = {
  users: {
    allUsers: 'SELECT * FROM users'
  }
};

function query(query, params) {
  return new Promise((resolve, reject) => {
    pool.query(query, params, (err, res) => {
      if (err) {
        reject(err);
      }
      resolve(res);
    });
  });
};

function getUsers() {
  return query(queries.users.allUsers);
};

getUsers()
  .then(res => {
    console.log(res);
  })
  .catch(err => {
    console.error(err);
  });