How to cteate a Node inside Main Node of Firebase database? - android

how we create node inside a node in firebase android...i need to creat blood_Group node inside kchzdjn...

The simples way to achieve this is to use updateChildren() method directly on your reference like this:
DatabaseReference rootRef = FirebaseDatabase.getInstance().getReference();
DatabaseReference sessionIdRef = rootRef.child("sessions").child(sessionId);
Map<String, Object> map = new HashMap<>();
map.put("blood_Group", "");
sessionIdRef.updateChildren(map);
In which sessionId is the unique key generated by the push() method.
Hope it helps.

Related

firebase replaced my data when restarting my app

My app will generate a gameKey everytime user logged in and clicked "start game" button. Variable "gameKey" is generated by the following code, and then I will save data under the gameKey. The problem is, whenever I restart my app, the Firebase replaced the whole data tree with a new gameKey generated.
What I would like to do is to generate a new gameKey without overwriting the old data every time when my app runs. It would be so glad if anyone can point out my problem, thanks so much!
final FirebaseDatabase database = FirebaseDatabase.getInstance();
UserId = mAuth.getCurrentUser().getUid();
DatabaseReference currentUserId = database.getReference("user").child(UserId);
gameKey = currentUserId.child("gameinfo").push().getKey();
Map<String, Object> game = new HashMap<>();
game.put(gameKey, new Game(tv_player1name.getText().toString(), tv_player2name.getText().toString(), tv_player3name.getText().toString(), tv_playerMename.getText().toString(), gameMode, gameDate ));
currentUserId.child("gameInfo").updateChildren(game);
Firebase Data:
- user
- 5xGKRXeHgThQy70lduPEp3mosTj1 (UID)
- gameInfo
-LLV0H0ZJwYT5M42Obfb
gameDate: "20180903_232015"
gameType: "HKMJ"
player1name: "peter"
player2name: "jenny"
player3name: "john"
player4name: "wilson"
*This is the gameKey generated: "LLV0H0ZJwYT5M42Obfb"
This is the code after your suggestions:
final FirebaseDatabase database = FirebaseDatabase.getInstance();
DatabaseReference currentUserId = database.getReference("user").child(UserId);
currentUserId.setValue(new User(mAuth.getCurrentUser().getEmail(), UserPic));
gameKey = currentUserId.child("gameinfo").push().getKey();
Map<String, Object> game = new HashMap<>();
game.put(gameKey, new Game(tv_player1name.getText().toString(), tv_player2name.getText().toString(), tv_player3name.getText().toString(), tv_playerMename.getText().toString(), gameMode, gameDate ));
currentUserId.child("gameInfo").child(gameKey).updateChildren(game);
In addition, I tried to replace this line
game.put(gameKey, new Game(tv_player1name.getText().toString(), tv_player2name.getText().toString(), tv_player3name.getText().toString(), tv_playerMename.getText().toString(), gameMode, gameDate ));
with this line, same result
Game game = new Game(tv_player1name.getText().toString(), tv_player2name.getText().toString(), tv_player3name.getText().toString(), tv_playerMename.getText().toString(), gameMode, gameDate );
Appreciate so much for the help!
Firebase ScreenShot
To solve this, please change the following line of code:
currentUserId.child("gameInfo").updateChildren(game);
to
currentUserId.child("gameInfo").child(gameKey).updateChildren(game);
You are basically generating a random key but you aren't using it at all. So you need to pass the gameKey to the child() method as seen in my above code.
Edit: So solve the entire update process, please use the following lines of code:
String uid = FirebaseAuth.getInstance().getCurrentUser().getUid();
DatabaseReference rootRef = FirebaseDatabase.getInstance().getReference();
DatabaseReference gameInfoRef = rootRef.child("user").child(uid).child("gameInfo");
String key = gameInfoRef.push().getKey();
Map<String, Object> game = new HashMap<>();
game.put("player1name", tv_player1name.getText().toString());
game.put("player2name", tv_player2name.getText().toString());
game.put("player3name", tv_player3name.getText().toString());
game.put("playerMename", tv_playerMename.getText().toString());
game.put("gameMode", gameMode);
game.put("gameDate", gameDate);
gameInfoRef.child(key).updateChildren(game);

Update object's field in Firebase

My project has 2 Apps: Admin-app and Client-app. First, I need to use the Admin-app in order to put data into Firebase and here is my data class
public class AllData {
private String placeName;
private ArrayList<String> category;
private String address;
private String openingHour;
private String website;
private HashMap<String, String> review; }
and I use following code to set data into Firebase
AllData alldata = new AllData(placeName, category, address,
, openingHour, website, null);
mDatabaseReference = mFirebaseDatabase.getReference().child("Store Data");
DatabaseReference storeData = mDatabaseReference.child(placeName);
storeData.setValue(alldata);
I have set the review field as null because I want to let my users review each place on Client-app and sync it into Firebase to the review field as HashMap<UserName, Review>
I use these codes in client-app to push review to Firebase
HashMap<String, String> reviewMap = new HashMap<>();
reviewMap.put(UserName, review);
mDatabase = FirebaseDatabase.getInstance();
mReference = mDatabase.getReference().child("Store Data").child(selectedPlace.placeName).child("review");
mReference.push().setValue(reviewMap);
This is not a right approach but that's all I could. What I want is to update the user's review to the AllData's review field in the Firebase asynchronously. How can I make this happen? Every answer is appreciated!
You can simply use setValue() method directly on the reference without using a HashMap like this:
DatabaseReference rootRef = FirebaseDatabase.getInstance().getReference();
rootRef.child("Store Data").child(selectedPlace.placeName).child("review").setValue(yourValue);
In which yourValue is the value which you want to set to the review key.
Hope it helps.

Getting Value from specified Key - Firebase/Android

I have run into an issue where I have each child off the root be a separate user account with a object (converted to string through gson). I create each user in the database during user registration.
DatabaseReference root = FirebaseDatabase.getInstance().getReference().getRoot();
Map<String,Object> map = new HashMap<String, Object>();
map.put(firebaseAuth.getCurrentUser().getUid(), "");
root.updateChildren(map);
Then save the user object in it using this method
FirebaseAuth firebaseAuth = FirebaseAuth.getInstance();
DatabaseReference databaseReference = FirebaseDatabase.getInstance().getReference().child(firebaseAuth.getCurrentUser().getUid());
Gson gson = new Gson();
String json = gson.toJson(this);
databaseReference.setValue(json);
Now I want to be able to pull the json from the firebase database but I can only get the userID key not the value. I am trying to avoid using a listener also.
This is how my database looks now:
-myapp-aaf46
-(userID): {json string}
I need to be able to get json string but I can only get it to return userId

Give unique child Key value for User using Firebase push() Method

How to give user defined key value in push(), instead of unique value created by push?
This is what am currently doing:
User user = new User(Editname.getText().toString(),
Editpid.getText().toString(),Editsem.getText().toString());
mRef.child("users").push().setValue(user);
.push() will create a new item with a unique reference.
You can use updateChildren() to update instead. For example,
User user=new User(Editname.getText().toString(),Editpid.getText().toString(),Editsem.getText().toString());
Map<String, Object> itemValues = user.toMap();
Map<String, Object> childUpdates = new HashMap<>();
// Define the key value here
String username = "yourKeyValueHere";
childUpdates.put("/users/" + username, itemValues);
mDatabase.updateChildren(childUpdates);
You might have to add something similar to the following to your User class.
#Exclude
public Map<String, Object> toMap() {
HashMap<String, Object> result = new HashMap<>();
result.put("name", name);
result.put("pid", pid);
result.put("sem", sem);
return result;
}
Simplest way is to specify the child key with the child method:
User user = new User(Editname.getText().toString(),
Editpid.getText().toString(),Editsem.getText().toString());
mRef.child("users").child(user.pid).setValue(user);
Where I specify user.pid, you can use whatever unique key you use to identify the user (typically when using Firebase Authentication this would be user.getUid()).
This is one way to do it assuming we want to use the User's name as unique key:
User user = new User(Editname.getText().toString(),
Editpid.getText().toString(),Editsem.getText().toString());
String uniqueKey = user.getName();
//You could use something else for quick reference since two users can have the same name
mDatabaseReference.child("users").child(uniqueKey).push().setValue(user);

How to delete multiple nodes in one request in firebase?

I have two nodes from one root and I want to delete the data from both of them in one request. Both sub-nodes has the same key. I tried this:
Firebase firebaseRef = new Firebase(<root_path>);
Map<String, Object> childUpdates = new HashMap<>();
childUpdates.put(<path_to_first_node>, key);
childUpdates.put(<path_to_second_node>, key);
listToRemoveRef.updateChildren(childUpdates, null);
But it removed data from only the first node
It looks like you're using the updateChildren function wrong. What you want to do is this
Firebase firebaseRef = new Firebase(<root_path>);
Map<String, Object> childUpdates = new HashMap<>();
childUpdates.put("<path_to_first_node>" + key, null);
childUpdates.put("<path_to_second_node>" + key, null);
listToRemoveRef.updateChildren(childUpdates);
The second parameter to updateChildren doesn't set the value to null it is an optional completion listener (see documentation). So instead of passing null to it on the last line, you can just omit it.

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