CODEWITHSUNDEEP
javascriptmysqlnode.jsmodule
sakib11
sakib11

Reputation: 536

Best way to structure a mysql+nodejs+express app

I use mysql (without sequelize) and generally create the connection in a module.export function which I then require from other files like so:

var db;
module.exports={
getConnection = function (){return new Promise(function(resolve, reject){
// db = mysql connection stuff
resolve(db)
});}, 
//other database related operations similarly
}

Now, I want to separate everything for example, I want to have a userModel that will have a few database operations related to users which will just import the db connection and so on; But what is the optimal way of achieving this? Thanks.

Upvotes: 0

Views: 107

Answers (1)

dusthaines
dusthaines

Reputation: 1350

Since it's used so broadly and doesn't present a high risk of variable naming conflict, I prefer to add it to the global object. Then you never have to make sure it's being included, passed, or imported from a module.

Consider the following example:

// in your application initialization file such as app.js

// require items …
const mysql = require('mysql');

const connection = mysql.createPool({
  connectionLimit: 10,
  host: process.env.DB_HOST || '127.0.0.1',
  user: process.env.DB_USER || 'local_user',
  password: process.env.DB_PASSWORD || 'local_password',
  database: process.env.DB_NAME || 'local_database',
  multipleStatements: true, 
  charset: 'utf8mb4' // necessary if you might need support for emoji characters
});

connection.on('connection', function (connection) {
  // handy for testing
  console.log('Pool id %d connected', connection.threadId);
});

connection.on('enqueue', function () {
  // handy for testing
  console.log('Waiting for available connection slot');
});

// make the connection global via the the variable db
global.db = connection;


// everywhere else in your app, use the now global db variable when running queries

  db.query(
    'INSERT INTO users SET ?', [{name: "John Smith"}], function(error, results, fields) {
      if (error) throw error;
      console.log(results);
    });
  }

Upvotes: 1

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