CODEWITHSUNDEEP
androidfirebase-realtime-database
Venky
Venky

Reputation: 2047

How to retrieve data from a child node in Android Firebase

I already have a onDataChange written to get values from a different child node,but what I need is to change the key to let's say "new" and then retrieve the data from that child

Any inputs would be appreciated ..

Upvotes: 0

Views: 238

Answers (1)

AtaerCaner
AtaerCaner

Reputation: 712

As far as i understand, you want to change a field and bring back the changed data.

enter image description here

for e.g, for this data structure, if you want the change Username, create a User modal with different name, User newUser = new User("https://...","newUserName). And change the field in User modal

public String Profile;
public String newKey;

Then give the new modal to that uid,

FirebaseDatabase.getInstance().getReference().child("Users").child("ECWHIksxJ0Q5SUIIrev4BjnjmrJ3").setValue(newUser, new DatabaseReference.CompletionListener() {
                    @Override
                    public void onComplete(DatabaseError databaseError, DatabaseReference databaseReference) {
                        DatabaseReference yourRef = databaseReference.getRef();
                    }
                });

Now you have the changed data's reference. Did you try something like this?

Update:

If you want to update multiple value/field with single action, you should create a map and put every path into it with values.

In firebase, every table, every specific field is an path. Consider the data structure shown above. If you want change Username field:

HashMap<String, Object> updateMap = new HashMap<>();

updateMap.put("/Users/ECWHIksxJ0Q5SUIIrev4BjnjmrJ3/Username", "newUserName");

For different user:

updateMap.put("/Users/DIFFERENT_USER_KEY/Username", "newUserName2");

For diffrent table:

updateMap.put("/YourOtherTable/DifferentPath/DifferentField", true);

Then get your database root reference and update all at once.

FirebaseDatabase.getInstance().getReference().updateChildren(updateMap).addOnCompleteListener(new OnCompleteListener...)

This is very simple way to update a lot of things in one action, but it's causing problems when writing firebase rules. Because you get your root reference and try to set a value to it. The choice is yours.

Upvotes: 1

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