Need help searching for a value in firestore

Question

I\'m new to firestore and I\'m making a register page with vue. Before a new user is made, it has to check if the given username already exists or not and if not, make a new us

Answer 1

Link to documentation: https://firebase.google.com/docs/firestore/query-data/queries#simple_queries

You can where this query, which is beneficial to you in multiple ways:

1: Fewer docs pulled back = fewer reads = lower cost to you.

2: Less work on the client side = better performance.

So how do we where it? Easy.

db.collection("Users")
           .where("username", "==", this.username)
           .get()
           .then(querySnapshot => {
             //Change suggested by Frank van Puffelen (https://stackoverflow.com/users/209103/frank-van-puffelen)
             //querySnapshot.forEach(doc => {
             //  if (this.username === doc.data().username) {
             //    usernameExist = true;                              
             //  }
             //});
             usernameExists = !querySnapshot.empty 
           });