Firebase query object key in array with Javascript

Question

I have a db structure as:

user = {
 name: 'xxx',
 address: 'XXX YY ZZZ',
 updates: [
  {
    created: '09/03/2022',
    content: { message: 'Message #1132'},
    ....
  }
 ]
}

I want to query any user that have updates.content.message contains the word 'Message' with firebase web version.

Thanks a lot!

Answer 1

There's no native like query on Google Cloud Firestore. But you can manage to create a workaround using nodejs/javascript. See code below:

var collection = "user";

// search input. you can change this to any word like in the comment you said that you want to find document that contains "test".
search = "Message";

// gets the length of the search input.
searchLength = search.length;

// logically change the last character of the search input to imitate the `like` query.
searchFront = search.slice(0, searchLength-1);
searchEnd = search.slice(searchLength-1, search.length);
// will result to "Messagf".
end = searchFront + String.fromCharCode(searchEnd.charCodeAt(0) + 1);

const query = db
.collection(collection)
.where('updates.content.message', '>=', search).where('updates.content.message', '<', end)
.get()
.then((querySnapshot) => {
    querySnapshot.forEach((doc) => {
        console.log(doc.id, ' => ', doc.data());
    });
});

The above code will search the updates.content.message that contains the word 'Message'. I leave some comments on the code for a better explanation. I'm not sure though if you're using Firestore v8 or v9 but the above code is written on v8.

Result:

drh13VT3T6n5bBHNARYD  =>  {
  address: 'XXX YY ZZZ',
  name: 'xxx',
  updates: { created: '09/03/2022', content: { message: 'Message #1132' } }
}