Cannot read property 'query' of undefined

I am sorry to be the first that is starting an open issue. My implementation returns Cannot read property ‘query’ of undefined error

var con;
mysql.createConnection({
    host: config.db.host,
    user: config.db.username,
    password: config.db.password,
    database: config.db.database
}).then(function(connection){
    con = connection;
});

con.query(queries.allUsers).then(function (err, users) {
    console.log(users);
});

What could I have done better?

[christiannwamba]

@lukeb-uk Ok. We call it a day then…

[CodeFoodPixels]

The doc examples aren’t wrong, but they probably aren’t the best for those unfamiliar with promises. I’ll have a look at clarifying them.