storing arrays into object datatype into firestore in android and iOS(swift)

Question

Hi I have 2 arrays like phonenumber[1,2,3] amount[10,20,30] I need to store the data in a single document like field1: 1 field2: 10

The code I tried is

I took the object like **

public class Pojo {
    String invitee;
    Map<Integer,Integer>phoneAmount;
    public Pojo(String invitee, Map<Integer, Integer> phoneAmount)
    {
      this.invitee = invitee;
        this.phoneAmount=phoneAmount;
    }
}**

And in another class

 Map<int[], int[]> phoneAmount = new HashMap<>();
               phoneAmount.put(phonenumber,amount);


db.collection("Split").document("invitees").set(phoneAmount).addOnSuccessListener(new OnSuccessListener<Void>() {
                @Override
                public void onSuccess(Void aVoid) {
                    Log.d(TAG, "DocumentSnapshot successfully written!");
                }
            })
                    .addOnFailureListener(new OnFailureListener() {
                        @Override
                        public void onFailure(@NonNull Exception e) {
                            Log.w(TAG, "Error writing document", e);
                        }
                    });

It shows error like java.lang.RuntimeException: Could not serialize object. Maps with non-string keys are not supported at com.google.android.gms.internal.zzejw.zza(Unknown Source) at com.google.android.gms.internal.zzejw.zza(Unknown Source) at com.google.android.gms.internal.zzejw.zzbp(Unknown Source)

try using pojo class with one String field and one Map<int,int> phoneAmount and a constructor public YourPojoClass(String title, Map<int,int> phoneAmount ) . By this you can add items to phoneAmount object like phoneAmount.put(phoneNumber, amount); and then add document to collection reference like db.collection("Split").document("lahari").set(yourPojoClass) after creating object of your PojoClass like MyPojo pojo= new MyPojo ("invite", phoneAmount ); — Mohammed Farhan
– Mohammed Farhan, Commented Feb 13, 2018 at 4:57
@MohammedFarhan can you show me an example of this scenario. I am in confusion state — Lahari Areti
– Lahari Areti, Commented Feb 13, 2018 at 6:21
please follow Alex answer below, its similar to my comment and will suffice your requirement. — Mohammed Farhan
– Mohammed Farhan, Commented Feb 13, 2018 at 6:43

Alex Mamo · Accepted Answer · 2018-08-13 10:54:17Z

2

From the official documentation:

Although Cloud Firestore can store arrays, it does not support querying array members or updating single array elements.

This approach is one that I personally don't recommend it to be used. One of the many reasons also Firebase recommends against using arrays is that it makes the security rules impossible to write.

However, you can still model this kind of data by leveraging the other capabilities of Cloud Firestore.

Let's take an example. Suppose you have a database which look like this:

{
    title: "My Book",
    categories: [
        "science",
        "computer science",
        "technology"
    ]
}

You need to know that if you want to query for all books that are part of the "science" category, using this data structure, there is no way to perform this query.

To solve this, you can consider an alternative data structure, where each category is the key in a map and all values are true.

{
    title: "My Book",
    categories: {
        "science": true,
        "computer science": true,
        "technology": true
    }
}

And to query your database you can use this query:

db.collection("books")
    .whereEqualTo("categories.science", true)
    .get()
    .addOnCompleteListener(new OnCompleteListener<QuerySnapshot>() {/* ... */});

For your particular case, you can use a database structure that looks like this:

{
    title: "phonenumber",
    categories: {
        "12345": true,
        "67890": true,
        "43215": true
    }
}

To query, please use the following code:

db.collection("phonenumbers")
    .whereEqualTo("categories.12345", true)
    .get()
    .addOnCompleteListener(new OnCompleteListener<QuerySnapshot>() {/* ... */});

Edit 13 Aug 2018:

According to the updated documentation regarding array membership, now it is possible to filter data based on array values using whereArrayContains() method. A simple example would be:

CollectionReference citiesRef = db.collection("cities");
citiesRef.whereArrayContains("regions", "west_coast");

This query returns every city document where the regions field is an array that contains west_coast. If the array has multiple instances of the value you query on, the document is included in the results only once.

edited Aug 13, 2018 at 10:54

answered Feb 13, 2018 at 6:38

Alex Mamo

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13 Comments

Lahari Areti Over a year ago

I need to query the phone number

Mohammed Farhan Over a year ago

@Alex Mamo, Hello Again. This must be the answer for OP. Please give OP the structure of POJO class.

Lahari Areti Over a year ago

what do u mean by op and pojo class

Alex Mamo Over a year ago

Please see my updated answer. OP is Original Poster and a POJO class is Plain Old Java Object.

Lahari Areti Over a year ago

kk I got it How to add to database

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