I'm new to Android development ... ;-)
I need to know how to read a specific document I saved to Firestore, without having to copy the "documentPath" manually from the Cloud Firestore Console!
How do you do this automatically?
Next, I put some of the code where the documentPath is that I need to configure:
DocumentReference user = mFirestore.collection("Users").document(idUsers).collection("Companies").document(**"documentPath"**)
link to the image:
Company that I registered now and that I wish to need to show the user automatically
link to the document:
Document fields
I'm testing the following class:
private void ReadSingleEmpresa() {
FirebaseAuth autenticacao = ConfiguracaoFirebase.getFirebaseAutenticacao();
String idUsuario = Base64Custom.codificarBase64(autenticacao.getCurrentUser().getEmail());
DocumentReference user = mFirestore.collection("Users").document(idUsuario).collection("Companies").document("gaSpr59pbeMmO9UpFxQQ");//document path
user.get().addOnCompleteListener(new OnCompleteListener<DocumentSnapshot>() {
#Override
public void onComplete(#NonNull Task<DocumentSnapshot> task) {
if (task.isSuccessful()) {
DocumentSnapshot document = task.getResult();
if (document.exists()) {
Log.d("ler doc", "DocumentSnapshot data: " + document.getData());
StringBuilder fields = new StringBuilder("");
//Some document fields
fields.append("Company name: ").append(document.get("nomeEmpresa"));
fields.append("\nEmail: ").append(document.get("emailRepresentante"));
fields.append("\nTelephone number: ").append(document.get("telefoneRepresentante"));
txtEmpresa.setText(fields.toString());
} else {
Log.d("ler doc", "No such document");
}
} else {
Log.d("ler doc", "get failed with ", task.getException());
}
}
})
.addOnFailureListener(new OnFailureListener() {
#Override
public void onFailure(#NonNull Exception e) {
}
});
}
This is the result:
Result of reading some document fields
It works but I do not know how to get the document I just registered among several. I only get it when I manually copy the document ID ...
Related
I want to retrieve data stored as a map field on Cloud Firestore.
I want to get the 'Comment' as a string from 'All Comments' field to show it in a TextView.
How can I do it? (Java)
I tried this to add the data
Map<String,String> allComments=new HashMap<String,String>();
String commentContent=commentboxedittext.getText().toString();
allComments.put("Movie Name",name);
allComments.put("Comment",commentContent);
firebaseFirestore.collection("All Comments").document("MovieComments").set(allComments, SetOptions.merge());
And this to retrieve the data
DocumentReference docRef = firebaseFirestore.collection("All Comments").document("MovieComments");
docRef.get().addOnCompleteListener(new OnCompleteListener<DocumentSnapshot>() {
#Override
public void onComplete(#NonNull Task<DocumentSnapshot> task) {
if (task.isSuccessful()) {
DocumentSnapshot document = task.getResult();
if (document.exists()) {
Map<String, Object> m=document.getData();
userComment=m.get("Comment").toString();
mName=m.get("Movie Name").toString();
} else {
Toast.makeText(MovieDetails.this, "No Such Document", Toast.LENGTH_SHORT).show();
}
} else {
Toast.makeText(MovieDetails.this, "Error", Toast.LENGTH_SHORT).show();
}
}
});
But app crashes on doing this.
I also tried doing this to put the data and it worked but then I do not know how to retrieve data form this method.
Map<String,String> allComments=new HashMap<String,String>();
Map<String, Object> user=new HashMap<String,Object>();
userID=firebaseAuth.getCurrentUser().getUid();
userReference=firebaseFirestore.collection("Users ").document(userID);
String commentContent=commentboxedittext.getText().toString();
allComments.put("Movie Name",name);
allComments.put("Comment",commentContent);
user.put("All Comments",allComments);
userReference.set(user, SetOptions.merge()).addOnSuccessListener(new OnSuccessListener<Void>() {
#Override
public void onSuccess(Void unused) {
Toast.makeText(MovieDetails.this, "Comment Added", Toast.LENGTH_SHORT).show();
}
}).addOnFailureListener(new OnFailureListener() {
#Override
public void onFailure(#NonNull Exception e) {
if(e instanceof FirebaseNetworkException)
Toast.makeText(MovieDetails.this, "No Internet Connection", Toast.LENGTH_SHORT).show();
Toast.makeText(MovieDetails.this, "Values Not Stored", Toast.LENGTH_SHORT).show();
}
});
Assuming that "l4ir...Xy12" is ID of the authenticated user, to get the value of the "Comment" that exists within the "All Comments" map, please use the following lines of code:
String uid = FirebaseAuth.getInstance().getCurrentUser().getUid();
FirebaseFirestore db = FirebaseFirestore.getInstance();
db.collection("users").document(uid).get().addOnCompleteListener(new OnCompleteListener<DocumentSnapshot>() {
#Override
public void onComplete(#NonNull Task<DocumentSnapshot> task) {
if (task.isSuccessful()) {
DocumentSnapshot document = task.getResult();
if (document.exists()) {
String comment = ((HashMap<String, Object>) document.getData().get("All Comments")).get("Comment").toString();
Log.d("TAG", comment);
} else {
Log.d("TAG", "No such document");
}
} else {
Log.d("TAG", "get failed with ", task.getException());
}
}
});
The result in the logcat will be:
sfgs
A few things to note:
DocumentSnapshot#get(String field) returns an object of type Object. Since each field inside a document represents a pair of keys and values, we can cast the result to an object of type HashMap<String, Object>.
Since we already have a Map, we can get the call Map#get(Object key) method, which returns the value associated with the key.
I'm new to NoSQL databases, but I'm attempting to use Firestore with an Android mobile application I'm developing.
I can write to the DB without any issues, but I can't read data. See code below:
DocumentReference docRef = db.collection("users").document("abc#gmail.com");
docRef.get().addOnSuccessListener(new OnSuccessListener<DocumentSnapshot>() {
#Override
public void onSuccess(DocumentSnapshot documentSnapshot) {
User userFromDB = documentSnapshot.toObject(User.class);
}
});
When I was debugging, program execution didn't enter the 'onSuccess' function.
The code I'm using is based off the documentation (Get Data with Cloud Firestore - Custom Objects). I made sure that the 'User' fields in my code match the ones in the DB, and they all have 'get' methods.
Also, these are my rules:
match /{document=**} {
allow read, write: if true
}
I've been stuck on this for a while, any help would be highly appreciated.
The onSuccessListener is for write actions to the database. For getting data you need to use the onCompletedListener as shown in the official documentation:
DocumentReference docRef = db.collection("users").document("abc#gmail.com");
docRef.get().addOnCompleteListener(new OnCompleteListener<DocumentSnapshot>() {
#Override
public void onComplete(#NonNull Task<DocumentSnapshot> task) {
if (task.isSuccessful()) {
DocumentSnapshot document = task.getResult();
if (document.exists()) {
Log.d(TAG, "DocumentSnapshot data: " + document.getData());
} else {
Log.d(TAG, "No such document");
}
} else {
Log.d(TAG, "get failed with ", task.getException());
}
}
});
I'm making a simple app in which I want to introduce most liked posts. I'm using Cloud Firestore. My question is how the query should look like in this case? (I'm using Java)
Here's the Firestore tree:
-ROOT
--Posts
---Post
----Likes
Likes collection is set of users' ids.
Assuming that the Likes property is of type number and not String, please use the following code:
FirebaseFirestore rootRef = FirebaseFirestore.getInstance();
DocumentReference ref = rootRef.collection("Posts").document("Post");
ref.get().addOnCompleteListener(new OnCompleteListener<DocumentSnapshot>() {
#Override
public void onComplete(#NonNull Task<DocumentSnapshot> task) {
if (task.isSuccessful()) {
DocumentSnapshot document = task.getResult();
if (document.exists()) {
long numberOfLikes = document.getLong("Likes");
Log.d(TAG, String.valueOf(numberOfLikes));
} else {
Log.d(TAG, "No such document");
}
} else {
Log.d(TAG, "get failed with ", task.getException());
}
}
});
The output in your logcat will be the number of likes.
This question already has answers here:
How to delete document from firestore using where clause
(12 answers)
Closed 9 months ago.
Is there a way I can perform a delete on Firestore documents where field1 =x and field2 = y?
I see the delete function but does not come with where.
If I use the transaction then there is get and delete but the get does not seem to accept "where" clause.
I hope I am missing something in the documentation.
Thanks
To achieve this, you need to create the desired query first and then just use the delete() method like this:
FirebaseFirestore rootRef = FirebaseFirestore.getInstance();
CollectionReference itemsRef = rootRef.collection("yourCollection");
Query query = itemsRef.whereEqualTo("field1", "x").whereEqualTo("field2", "y");
query.get().addOnCompleteListener(new OnCompleteListener<QuerySnapshot>() {
#Override
public void onComplete(#NonNull Task<QuerySnapshot> task) {
if (task.isSuccessful()) {
for (DocumentSnapshot document : task.getResult()) {
itemsRef.document(document.getId()).delete();
}
} else {
Log.d(TAG, "Error getting documents: ", task.getException());
}
}
});
Here's my method for both querying and deleting documents from firestore. First it queries the data, then it deletes it.
Note, this method must be adapted for integer/double values.
public void whereQueryDelete(final String collection, final String field, final String value) {
mFirestoreDatabase.collection(collection)
.whereEqualTo(field, value)
.get()
.addOnCompleteListener(new OnCompleteListener<QuerySnapshot>() {
#Override
public void onComplete(#NonNull Task<QuerySnapshot> task) {
if (task.isSuccessful()) {
for (QueryDocumentSnapshot document : task.getResult()) {
Log.d(TAG, document.getId() + " => " + document.getData());
String idDelete = document.getId();
mFirestoreDatabase.collection(collection).document(idDelete)
.delete()
.addOnSuccessListener(new OnSuccessListener<Void>() {
#Override
public void onSuccess(Void aVoid) {
Log.d(TAG, "DocumentSnapshot successfully deleted!");
}
})
.addOnFailureListener(new OnFailureListener() {
#Override
public void onFailure(#NonNull Exception e) {
Log.w(TAG, "Error deleting document", e);
}
});
}
} else {
Log.d(TAG, "Error getting documents: ", task.getException());
}
}
});
}
Let's say I have a userSnapshot which I have got using get operation:
DocumentSnapshot userSnapshot=task.getResult().getData();
I know that I'm able to get a field from a documentSnapshot like this (for example):
String userName = userSnapshot.getString("name");
It just helps me with getting the values of the fields, but what if I want to get a collection under this userSnapshot? For example, its friends_list collection which contains documents of friends.
Is this possible?
Queries in Cloud Firestore are shallow. This means when you get() a document you do not download any of the data in subcollections.
If you want to get the data in the subcollections, you need to make a second request:
// Get the document
docRef.get().addOnCompleteListener(new OnCompleteListener<DocumentSnapshot>() {
#Override
public void onComplete(#NonNull Task<DocumentSnapshot> task) {
if (task.isSuccessful()) {
DocumentSnapshot document = task.getResult();
// ...
} else {
Log.d(TAG, "Error getting document.", task.getException());
}
}
});
// Get a subcollection
docRef.collection("friends_list").get()
.addOnCompleteListener(new OnCompleteListener<QuerySnapshot>() {
#Override
public void onComplete(#NonNull Task<QuerySnapshot> task) {
if (task.isSuccessful()) {
for (DocumentSnapshot document : task.getResult()) {
Log.d(TAG, document.getId() + " => " + document.getData());
}
} else {
Log.d(TAG, "Error getting subcollection.", task.getException());
}
}
});