I'm having a problem similar to this person's: connect ECONNREFUSED - node js , sql
I'm trying to connect app.js to an existing database running as part of MAMP. MAMP runs mysql on port 8889; how do I tell node.js which port to find mysql on?
When you are initializing the mysql client, along with username and password, you can pass a different value for port.
const client = mysql.createClient({
  user: '??',
  password: '??',
  port: 8889
});
For those initializing the mysql connection object using mysql.createPool({...}), it's the same solution as the accepted answer. For Reference
   const connection = mysql.createPool({
      host: ...,
      port: 8889,
      user: ...,
      password: ...,
    });