Find documents by child value?

Question

I need to find all document IDs with name: "Nick", so I can update the score.

I have the following Firestore Database structure:

{
  "c4ca4238a0b923820dcc509a6f75849b": {
    title: "Tiger",
    user: {
      name: "Chris",
      score: 1
    }
  },
  "c81e728d9d4c2f636f067f89cc14862c": {
    title: "Lion",
    user: {
      name: "Nick",
      score: 2
    }
  }
}

From the documentation I see that I can find documents using where like this:

const dbQuery = query(collection(dbFirestore, "posts"), where("title", "==", "Tiger"));

const dbSnapshot = await getDocs(dbQuery);

dbSnapshot.forEach((result) => {
  console.log(result.id, " => ", result.data());
});

But I don't see anything about how to search by a child element (user.name)?

Are you using Firestore or the Realtime Database? – Renaud Tarnec May 10 '22 at 19:56 — Renaud Tarnec, May 10 '22 at 19:56
@RenaudTarnec I'm using the latest version of Firestore. – May 10 '22 at 20:04 — , May 10 '22 at 20:04

score 0 · Accepted Answer · answered May 11 '22 at 05:42

Firestore is a NoSQL database which inherits how you query on any other NoSQL database. To specify a query condition on fields in an embedded/nested document, use dot notation "field.nestedField". When querying using dot notation, the field and nested field must be inside quotation marks.

You could get all the documents from nested objects by using this sample query:

const dbQuery = query(collection(db, "posts"), where("user.name", "==", "Nick"));

const dbSnapshot = await getDocs(dbQuery);

dbSnapshot.forEach((result) => {
  console.log(result.id, " => ", result.data());
});

`where("user.name", "==", "Nick")` is way simplier than I thought it would be, lol! Thank you so much for your help! — , May 11 '22 at 06:10

Find documents by child value?

1 Answers1