Correctly using promises with node-mysql

Question

I have been trying to do a simple query and return the results with node-mysql however I had several problems. Originally I wrote it where there was no promise, but if I tried to access user after just doing a query if returned undefined

The solution I came up with is the following, is this a good way of doing it? I need to wait until the results come back so I can then send a signal to the frontend to say the player is loaded and can play. Do I need to create a new promise for each query? I have a few tables I need to get data from (That can't be done with joins)

class Player {
    constructor(user_id, socket, connection) {
        this.socket = socket;
        this.connection = connection;

        this.loadUser(user_id)
            .then(() => {
                console.log("loaded user", this.user);
            });
    }

    async loadUser(user_id) {
        let _self = this;
        return new Promise((resolve, reject) => {
            _self.connection.query(`SELECT * FROM users WHERE id = ${user_id}`, (err, res) => {
                this.user = res[0];
                resolve()
            });
        })
    }
}
```

Answer 1

Remove the async method call from the constructor, and make the async method return the instance (this):

class Player {
  constructor(user_id, socket, connection) {
    this.socket = socket;
    this.connection = connection;
  }

  async loadUser() {
    let _self = this;
    return new Promise((resolve, reject) => {
      _self.connection.query(`SELECT * FROM users WHERE id = ${this.user_id}`, (err, res) => {
        this.user = res[0];
        resolve(this)
      });
    })
  }
}

Then you can instantiate a new Player and wait for it to load the necessary data from the database, all in one line, like this:

const player = await new Player(user_id, socket, connection).loadUser();

Or like this:

new Player(user_id, socket, connection).loadUser().then(player => {

});