How to user filter with Firestore database in React Native?

Question

I want to filter the firestore query to get all docs that do not contain a specific value.

I used @react-native-firebase

import firestore from '@react-native-firebase/firestore';


  const getUnreadDocs = async () => {
    const unreadDocs = await firestore()
      .collection('rooms')
      .doc('aDRKtxbhG9g5IfbKcsa4')
      .collection('messages')
      .where('seen', 'not-in', ['7B6jaZngXeN7V4r3eRoDBdlcj6m2'])
      .get();

    console.log(`unreadDocs`, unreadDocs);
  };

docs return from the query

data-from-query

query-return-from-docs

How data is stored?

we have collection

rooms Collection -> Docs -> fields
         |
         V
     messages Collection -> Docs -> fields

rooms-collection-img

messages-collection-img1

messages-collection-img2

What should the query return? as we mention in query, docs should not contain 7B6jaZngXeN7V4r3eRoDBdlcj6m2 in the seen field

so, query should return only one doc i.e.

messages-collection-img1

https://firebase.google.com/docs/firestore/query-data/queries — Eduards, Apr 28 '22 at 09:13
Can you reproduce the problem with a hard-coded `value`? If so, can you show us that code instead, as well as a screenshot of a document that is returns by the query that you think should not be returned? — Frank van Puffelen, Apr 28 '22 at 14:32
Yes, I reproduce the problem with a hard-coded `value`, I updated the docs in question. — Meet Patel, Apr 29 '22 at 08:58

score 0 · Accepted Answer · answered Apr 29 '22 at 13:59

The in/not-in operators checks if a current single-value field has a value that exists/does not exist in a list of values you specify. But your seen field is an array, which won't work with this operator.

Instead you'll want to use array-contains on that to check if a value is present. There is no equivalent array-does-not-contain operator to check whether a value is not present in the array field.

Also see:

How to user filter with Firestore database in React Native?

1 Answers1