How to get all documents from collection according to specific field from Firestore

Question

I have this data in "Firestore", I want to get all documents according to "city" like all users who have city "karachi" and stored in arrayList of type "chatModel" I want to show this data in recyclerView

Here is the image of dataabase:

I have tried this but it's only getting me the last document from collection.

      firestore.collection("USERS")
        .whereEqualTo("city",cityName)
        .get()
        .addOnSuccessListener { documents ->
            for (document in documents) {

                arrayList.add(document.toObject(chatModel::class.java))

                Log.i("Info", "${document.id} => ${document.data}")


            }

            val adapter = chatAdapter(context!!, arrayList)
            chatRecyclerView.layoutManager = LinearLayoutManager(context,
                LinearLayoutManager.VERTICAL,false)
            chatRecyclerView.adapter = adapter
            adapter.notifyDataSetChanged()
        }

Here is the Logcat result:

v21GH5sBi3SdIb3v3xsp3ob64S23 => {username=Muhammad Rizwan, Email=mr1017753@gmail.com, city=Karachi, ProfileImageUrl=https://firebasestorage.googleapis.com/v0/b/me2wee-1b547.appspot.com/o/USERS-MEDIA%2Fv21GH5sBi3SdIb3v3xsp3ob64S23?alt=media&token=193c4013-c580-45dc-b63d-fee1ef13caba}

Here is the screenshot of all documents which contain the city "Karachi" but it's only getting the last one

score 1 · Accepted Answer · edited Feb 25 '20 at 15:55

The most probable problem with lowercase and upper case. You're problem might be similar to this question

As I can see your described in database city value is karachi in lowercase but output you provided uppercase Result.

firestore.collection("USERS").get()
    .addOnSuccessListener { documents ->
        for (document in documents) {
            if(document.get("city").equals("karachi") || document.get("city").equals("Karachi")){
                arrayList.add(document.toObject(chatModel::class.java));
            }
        }

        val adapter = chatAdapter(context!!, arrayList)
        chatRecyclerView.layoutManager = LinearLayoutManager(context,
            LinearLayoutManager.VERTICAL,false)
        chatRecyclerView.adapter = adapter
        adapter.notifyDataSetChanged()
    }

score 0 · Answer 2 · edited Feb 25 '20 at 14:46

0

I have tried this but it's not working

It doesn't work because you are creating a chatAdapter object at every iteration of your for loop. To solve this, move the last four lines of code outside the loop. Inside the loop should exist only:

arrayList.add(document.toObject(chatModel::class.java))

In this way you populate the list and set the adapter only when the list is full of objects.

edited Feb 25 '20 at 14:46

Ashish

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answered Feb 25 '20 at 12:56

Alex Mamo

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Actually , The porblem is i am not getting the data in arrayList. I want to know how i can retrive the data – Android Geek Feb 25 '20 at 13:18
If you try to log `Log.d(TAG, document.toObject(chatModel::class.java).city)`, what is printed out in the logcat? – Alex Mamo Feb 25 '20 at 13:36
it's only getting the last document from firestore – Android Geek Feb 25 '20 at 13:48
It should print each and every name. Have you tried to get those lines out of the loop? – Alex Mamo Feb 25 '20 at 13:56
Yes i have tried all these code out of loop but its only getting me a last document – Android Geek Feb 25 '20 at 14:00
Edit your question and add the exact code that you are using now. – Alex Mamo Feb 25 '20 at 14:04
I see, in that case your query is returning a single user since only one of them has set the city to `Karachi`, right? That's the point, to return only with a specific city. – Alex Mamo Feb 25 '20 at 14:12
No , In my collection there are 3 documents with city "Karachi" but it's only getting the last document and this document is related to me as all the data stored in the document are mine – Android Geek Feb 25 '20 at 14:23
Please add a screenshot also with the other documents as well. – Alex Mamo Feb 25 '20 at 14:25
But it's the same with the first one `eDj7...`. Please add another one. – Alex Mamo Feb 25 '20 at 14:36

How to get all documents from collection according to specific field from Firestore

2 Answers2