var is not updating in JS

Question

I'm making an app with React and Express, and I'm facing a basic issue. I've created a let maxPlayers = 0; Then I call my DB to find the actual max players number :

let maxPlayers = 0;

// Here I ask my DB to count my players
db.query("SELECT * FROM cards", (err, rows) => {
       console.log(rows.length) // -> 30
       maxPlayers = rows.length // In my logic, 0 becomes 30
       console.log(maxPlayers)  // -> 30
   });

   console.log(maxPlayers)      // -> 0

What I want is myMaxPlayers to be set as 30 outside the db.query function.

I know this is a basic scope issue, but I've tryied everything i know and i struggle.