firebase get "documentreference" with "where" code example

Example 1: get data in from a collection firestore

db.collection("users").get().then((querySnapshot) => {
    querySnapshot.forEach((doc) => {
        console.log(`${doc.id} => ${doc.data()}`);
    });

Example 2: get doc id firestore

const racesCollection: AngularFirestoreCollection<Race>;
return racesCollection.snapshotChanges().map(actions => {       
  return actions.map(a => {
    const data = a.payload.doc.data() as Race;
    data.id = a.payload.doc.id;
    return data;
  });
});