I wrote the following code that deletes two documents from the cloud Firebase database:
fireDB.document(groupPath).collection("users").document(phoneNumber).delete().addOnSuccessListener(new OnSuccessListener<Void>() {
#Override
public void onSuccess(Void aVoid) {
fireDB.collection("users").document(phoneNumber).delete().addOnSuccessListener(new OnSuccessListener<Void>() {
#Override
public void onSuccess(Void aVoid) {
Log.d(this.getClass().getName(), "DocumentSnapshot successfully deleted");
Toast.makeText(getApplicationContext(),R.string.successfully_deleted_user,Toast.LENGTH_LONG).show();
finish();
}
}).addOnFailureListener(new OnFailureListener() {
#Override
public void onFailure(#NonNull Exception e) {
Log.w(this.getClass().getName(), "Error deleting document", e);
Toast.makeText(getApplicationContext(),R.string.failed_to_delete_user,Toast.LENGTH_LONG).show();
}
});
Log.d(this.getClass().getName(), "DocumentSnapshot successfully deleted");
}
}).addOnFailureListener(new OnFailureListener() {
#Override
public void onFailure(#NonNull Exception e) {
Log.w(this.getClass().getName(), "Error deleting document", e);
Toast.makeText(getApplicationContext(),R.string.failed_to_delete_user,Toast.LENGTH_SHORT).show();
}
});
The problem with that code is that it deletes first document and then deletes second document, meaning if the first try will delete it successfully and the second one will fail to delete it, there is going to be a problem. Is it possible to delete two documents in Firebase cloud database so the result could be of of the following two options:
Both of the documents are deleted.
Both of the document are not deleted.
Is it possible to do?
As robsiemb commented, you'll want to use a batch write or transaction for this.
As far as I can see, the equivalent from your code would be something like this:
// Get a new write batch
WriteBatch batch = db.batch();
DocumentReference docRef1 = fireDB.document(groupPath).collection("users").document(phoneNumber);
DocumentReference docRef2 = fireDB.collection("users").document(phoneNumber)
DocumentReference laRef = db.collection("cities").document("LA");
batch.delete(docRef1);
batch.delete(docRef2);
// Commit the batch
batch.commit().addOnCompleteListener(new OnCompleteListener<Void>() {
#Override
public void onComplete(#NonNull Task<Void> task) {
// ...
}
});
Related
I have realtime database in firebase it look like this
Now I want to delete value by key in android (java).
I have tried this code
DatabaseReference ref = FirebaseDatabase.getInstance().getReference();
ref.child("coating").child("88").removeValue().addOnSuccessListener(new OnSuccessListener<Void>() {
#Override
public void onSuccess(Void aVoid) {
Toast.makeText(activity, "on success", Toast.LENGTH_SHORT).show();
}
}).addOnFailureListener(new OnFailureListener() {
#Override
public void onFailure(#NonNull Exception e) {
Toast.makeText(activity, "on success"+e.getMessage(), Toast.LENGTH_SHORT).show();
}
});
I get success response in onSuccess Method but value in database is not deleted.
As per this document
check out last para about delete and update ui
I want to give the user in my app the possibility to delete his account so when he clicks on the delete button a document gets deleted which contains all his informations. The name of the document is his displayName so I get this as a string but when I run the code you are seeing below I get a NullpointerException in this line:
String currentUsername = user.getDisplayName();
even though the displayName is not null.
Edit:
I found the solution on my own, see the answer below.
Here is my method:
btn_delete_account.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
FirebaseUser user = FirebaseAuth.getInstance().getCurrentUser();
user.delete()
.addOnCompleteListener(new OnCompleteListener<Void>() {
#Override
public void onComplete(#NonNull Task<Void> task) {
if (task.isSuccessful()) {
deleteDocument();
}
}
});
}
});
...
public void deleteDocument (){
FirebaseUser user = FirebaseAuth.getInstance().getCurrentUser();
String currentUsername = user.getDisplayName();
db.collection("User").document(currentUsername)
.delete()
.addOnSuccessListener(new OnSuccessListener<Void>() {
#Override
public void onSuccess(Void aVoid) {
Log.d(TAG, "DocumentSnapshot successfully deleted!");
Toast.makeText(PersonalSettings.this, "Your account was successfully deleted.", Toast.LENGTH_SHORT).show();
Intent i = new Intent(PersonalSettings.this, SignInActivity.class);
startActivity(i);
finish();
}
})
.addOnFailureListener(new OnFailureListener() {
#Override
public void onFailure(#NonNull Exception e) {
Log.w(TAG, "Error deleting document", e);
}
});
}
First thing you have to check that current user is not null
FirebaseUser user = FirebaseAuth.getInstance().getCurrentUser();
if(user==null)
{
return;
}
if current user is not null then get its name and further check that it's name is not null.
String currentUsername = user.getDisplayName();
if(TextUtils.isEmpty(currentUsername))
{
return;
}
if name is not null then go for delete document as follows :
public void deleteDocument (){
FirebaseUser user = FirebaseAuth.getInstance().getCurrentUser();
if(user==null)
{
return;
}
String currentUsername = user.getDisplayName();
if(TextUtils.isEmpty(currentUsername))
{
return;
}
db.collection("User").document(currentUsername)
.delete()
.addOnSuccessListener(new OnSuccessListener<Void>() {
#Override
public void onSuccess(Void aVoid) {
Log.d(TAG, "DocumentSnapshot successfully deleted!");
Toast.makeText(PersonalSettings.this, "Dein Account wurde erfolgreich gelöscht.", Toast.LENGTH_SHORT).show();
Intent i = new Intent(PersonalSettings.this, SignInActivity.class);
startActivity(i);
finish();
}
})
.addOnFailureListener(new OnFailureListener() {
#Override
public void onFailure(#NonNull Exception e) {
Log.w(TAG, "Error deleting document", e);
}
});
}
I think you're misunderstanding the error. It's saying that user is null, not the display name. This means there is currently no user signed into the app. You will have to write some code to check for this case.
I also strongly suggest not using a display name as the ID for a document in Cloud Firestore. Since you're using Firebase Authentication, the user already has a unique ID assigned to their account. This is the preferred way to store per-user data.
I found the error:
I called my delete method after I used the user.delete() method which deletes the signed in user, so logically the displayName was also deleted.
I want to delete images from firebase storage.
This is my Firebase Database.
You need to use this method call:
StorageReference photoRef = mFirebaseStorage.getReferenceFromUrl(mImageUrl);
Then delete as you were:
photoRef.delete().addOnSuccessListener(new OnSuccessListener<Void>() {
#Override
public void onSuccess(Void aVoid) {
// File deleted successfully
Log.d(TAG, "onSuccess: deleted file");
}
}).addOnFailureListener(new OnFailureListener() {
#Override
public void onFailure(#NonNull Exception exception) {
// Uh-oh, an error occurred!
Log.d(TAG, "onFailure: did not delete file");
}});
I have created a database in firestore and loaded the test data successfully. But later I noticed that some data is missing in database. I found that when I load the same records with a different value for some fields the old record is replaced with the new record. I feel like this is the issue in the database design. I need to collect and save all the records even if it is a duplicate records at entire records level.
Could you please let me know how to do this ?
private void exportToFireStore() {
// Access a Cloud Firestore instance from your Activity
final FirebaseFirestore db = FirebaseFirestore.getInstance();
/* ----------------_-------Collection delete is not supported-----------------------
----------Hence get all the document (coins) for individual Docs delete----------
*/
//------------------------------- Getting document (coins) Ends ---------------------------------------------
final List<String> coinsFromFirestore = new ArrayList<>();
db.collection("cryptos").document(userEmailID).collection("coin")
.whereEqualTo("createdBy", userEmailID)
.get()
.addOnCompleteListener(new OnCompleteListener<QuerySnapshot>() {
#Override
public void onComplete(#NonNull Task<QuerySnapshot> task) {
if (task.isSuccessful()) {
for (QueryDocumentSnapshot document : task.getResult()) {
System.out.println("Testing 1 Batch Read done" + document.getData());
coinsFromFirestore.add(document.getData().get("coinname").toString());
}
//------------------------------- Getting document (coins) Ends ---------------------------------------------
if(coinsFromFirestore.size()>0){
for (int i=0;i<coinsFromFirestore.size();i++) {
if ( i<(coinsFromFirestore.size()-1) ) {
db.collection("cryptos").document(userEmailID).collection("coin").document(coinsFromFirestore.get(i))
.delete()
.addOnSuccessListener(new OnSuccessListener<Void>() {
#Override
public void onSuccess(Void aVoid) {
System.out.println("Testing 1 Successfully Deleted the document " );
}
})
.addOnFailureListener(new OnFailureListener() {
#Override
public void onFailure(#NonNull Exception e) {
System.out.println("Testing 1 Error Deleting the document ");
}
});
}else{
db.collection("cryptos").document(userEmailID).collection("coin").document(coinsFromFirestore.get(i))
.delete()
.addOnSuccessListener(new OnSuccessListener<Void>() {
#Override
public void onSuccess(Void aVoid) {
addTranToFireBaseeNow(db);
}
})
.addOnFailureListener(new OnFailureListener() {
#Override
public void onFailure(#NonNull Exception e) {
}
});
//!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! For last coin Ends !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
}
}
}else{
addTranToFireBaseeNow(db);
}
} else {
Log.d(TAG, "Error getting documents: ", task.getException());
}
}
});
//------------------------------- Getting document (coins) Ends ---------------------------------------------
}
private void addTranToFireBaseeNow(FirebaseFirestore db) {
WriteBatch batch = db.batch();
DocumentReference newCoinRef;
//CollectionReference cryptos = db.collection("cryptos");
List<Tran> tranList = getAllTranForFireStore();
String firebaseUID = FirebaseAuth.getInstance().getCurrentUser().getUid();
for (Tran t : tranList) {
Map<String, Object> tranData = new HashMap<>();
tranData.put("firebaseid", firebaseUID);
tranData.put("createdBy", userEmailID);
tranData.put("coinid", t.getCoinID());
tranData.put("coinname", t.getCoinName());
tranData.put("coinsymbol", t.getCoinSymbol());
tranData.put("date", String.valueOf(t.getDate()));
tranData.put("qty", String.valueOf(t.getQty()));
tranData.put("price", String.valueOf(t.getPrice()));
tranData.put("priceunit", String.valueOf(t.getPriceUnit()));
newCoinRef= db.collection("cryptos").document(userEmailID).collection("coin").document(t.getCoinName());
batch.set(newCoinRef, tranData);
}
batch.commit().addOnCompleteListener(new OnCompleteListener<Void>() {
#Override
public void onComplete(#NonNull Task<Void> task) {
// ...
}
});
}
No index is setup for my DB
Since you are using set without any options, it will overwrite the existing data. But your requirement is to merge your data, so you have to use the merge option as follows:
batch.set(newCoinRef, tranData, SetOptions.merge());
You can read more about options here.
Furthermore there is a good post which lists the differences between set, update and create.
You can use update and change one variable
reference.document("documentname").update("field", variable)
or
reference.document("documentname").set({
field: variable
}, { merge: true });
Or.. if you have to update an entire object, you can use:
reference.document("documentname").set(newObject, { merge: true });
Check this article:
https://saveyourtime.medium.com/firebase-cloud-firestore-add-set-update-delete-get-data-6da566513b1b
I'm trying to check to see if a value saved in the database matches the user selection, if it does then update it otherwise don't do anything.
I've tried the following, but get an exception:
Caused by: com.google.firebase.firestore.FirebaseFirestoreException: Every document read in a transaction must also be written.
Here's my code:
//update toolbar titles if they match
final DocumentReference adminDocRef = mDbase.collection("admins").document(adminID);
mDbase.runTransaction(new Transaction.Function<Void>() {
#Override
public Void apply(#NonNull Transaction transaction) throws FirebaseFirestoreException {
DocumentSnapshot adminSnapshot = transaction.get(adminDocRef);
String toolbarTitle = adminSnapshot.getString("displayedUser");
if (userName.equals(toolbarTitle)) {
transaction.update(adminDocRef, "displayedUser", userName);
}
// Success
return null;
}
})
.addOnSuccessListener(new OnSuccessListener<Void>() {
#Override
public void onSuccess(Void aVoid) {
Log.d(TAG, "Transaction success!");
}
})
.addOnFailureListener(new OnFailureListener() {
#Override
public void onFailure(#NonNull Exception e) {
Log.w(TAG, "Transaction failure.", e);
}
});
Are transactions capable of being conditional? If not how would you solve this problem? Seems silly to have to do a separate get then nest an update inside of it.
Any help would be greatly appreciated.
Thanks!
There is a similar answer from Alex ,from documentation
A transaction can fail for the following reasons:
The transaction contains read operations after write operations. Read operations must always come before any write operations. //not your case
The transaction read a document that was modified outside of the transaction. In this case, the transaction automatically runs again. The transaction is retried a finite number of times.
In your case I would try
if (userName.equals(toolbarTitle)) {
//transaction operations
}
See if that works!
So in order to update my toolbarTitle conditionally, I would have to cascade my Firestore operations this way:
DocumentReference adminDocRef = mDbase.collection("admins").document(adminID);
adminDocRef.get().addOnCompleteListener(activity, new OnCompleteListener<DocumentSnapshot>() {
#Override
public void onComplete(#NonNull Task<DocumentSnapshot> task) {
if (task.isSuccessful()) {
DocumentSnapshot document = task.getResult();
if (document.exists()) {
//assign document value to toolbarTitle
toolbarTitle = document.getString("displayedUser");
if (userName.equals(toolbarTitle)) {
DocumentReference adminDocRef = mDbase.collection("admins").document(adminID);
adminDocRef
.update("displayedUser", toolbarTitle)
.addOnSuccessListener(new OnSuccessListener<Void>() {
#Override
public void onSuccess(Void aVoid) {
Log.d(TAG, "Displayed child has been updated");
}
})
.addOnFailureListener(new OnFailureListener() {
#Override
public void onFailure(#NonNull Exception e) {
Log.w(TAG, "Error: updating displayed child", e);
}
});
Log.d(TAG, "DocumentSnapshot data: " + document.getData());
}
} else {
Log.d(TAG, "No such document");
}
} else {
Log.d(TAG, "get failed with ", task.getException());
}
}
});
It's a bit disappointing that I would have to do it this way, as it seems having it wrapped inside of a transaction would make more sense. I'm hoping that they allow conditional behavior inside the Transaction.
Actually, google has a class called Tasks in which you could use to make firestore calls synchronous.
So following your example, you could fix it into something like:
try {
DocumentSnapshot adminDocument = Tasks.await(adminDocRef.get());
if (adminDocument.exists()) {
String toolbarTitle = adminDocument.getString("displayedUser");
if (userName.equals(toolbarTitle)) {
Tasks.await(adminDocRef.update("displayedUser", userName));
//Success
}
}
} catch (ExecutionException e) {
//Error
e.printStackTrace();
} catch (InterruptedException e) {
//Error
e.printStackTrace();
}
This way you don't need listeners and at the same time it is a conditional update. I know this is late but hopefully it'll help someone.
[UPDATE]:
Please note that Tasks.await(...) call should not be called on the main thread, a solution would be using AsyncTask.