Cloud Firestore - Composite query

Question

I’m making a query in my database in the firestore, but when I put two where nested, I get the following error:

Error getting documents Error: Firestore: Operation was rejected because the system is not in a state required for the operation`s execution. (firestore/failed-precondition).

When I consult with only one of the Where, the query works.

Code:

firebase
  .firestore()
  .collection('users')
  .doc(userId)
  .collection('cars')
  .where('available', '==', true)
  .where('createdAt', '<=', new Date(moment().format('MMMM DD, YYYY')))
  .get()
  .then((snapshot) => {
      const cars = [];
      snapshot.forEach((doc) => {
        cars.push(Object.assign({}, { id: doc.id }, doc.data()));
      });
      this.setState({ cars, loading: false });
  })
  .catch((err) => {
      console.log('Error getting documents', err);
      this.setState({ loading: false });
  });

Answer 1

Seems related to this issue (and several others by the way).

That one answer in one of the related issues leads me to believe that the problem has to do with this excerpt in the firestore documentation, in the Indexes Compostos:

Cloud Firestore uses composite indexes to support composite queries that do not yet accept single field indexes. For example, you would need a composite index for the following queries:

citiesRef.where("country", "==", "USA").orderBy("population", "asc")
citiesRef.where("country", "==", "USA").where("population", "<", 3800000)
citiesRef.where("country", "==", "USA").where("population", ">", 690000)

For such consultations, for example, a composite index of country and population.

In your case, this index would have to be in available and createdAt.

Answer 2

Good afternoon,

Try the following, go to the firebase console, go to the firestore in the index tab and create a new composite Intel:

Collection: with the fields: available Ascending and createAt Ascending

i ran the following code successfully after creating the indices:

getCars(userId) {
    const now = new Date();
    this.db.firestore
      .collection('users')
      .doc(userId)
      .collection('cars')
      .where('available', '==', true)
      .where('createAt', '<=', now)
      .get()
      .then( res => {
        console.log(res.docs);
      });
  }