Im trying to get a list of user objects from firestore through a query. My current attempt looks like this:
List<User> getDiscoveryUsers(
String userId,
) async {
Query<Object?> query =
userCollection.where('finishedOnboarding', isEqualTo: true).limit(10);
var collection = await query.get();
//get the users list from query snapshot
var users = collection.docs.map((doc) => User.fromSnapshot(doc)).toList();
return users;
}
However I am getting the error:
Functions marked 'async' must have a return type assignable to 'Future'.
Try fixing the return type of the function, or removing the modifier 'async' from the function body.
I know there are a few similar questions on stack overflow, but i just cant seem to get this to work. Anyone know whats going on?
Thanks!
Just change the return type of your function from List<User> to Future<List<User>>.
Happy coding:)
your return type should be Future and must wait with await when running query on firestore.
Future<List<User>> getDiscoveryUsers(
String userId,
) async {
Query<Object?> query =
userCollection.where('finishedOnboarding', isEqualTo: true).limit(10);
var collection = await query.get();
//get the users list from query snapshot
var users = collection.docs.map((doc) => User.fromSnapshot(doc)).toList();
return users;
}
Related
void _getQuestions() async {
// Query Firestore for questions with the specified tags
Query query = await _firestore
.collection('questions')
.where('tags', arrayContainsAny: widget.tags);
QuerySnapshot querySnapshot = await query.getDocuments();
setState(() {
_questions = querySnapshot.documents;
});
importing cloud_firestore.dart.
I expected the errors to leave, but they are still around.
The method to get the documents is called get() in Flutter, not getDocuments().
I recommend keeping the Firebase documentation handy for this sort of thing, for this case that'd be the section on getting multiple documents from a collection
How to get docs id from some matching condition?
I was able to get this to work:
Future getChat({required String userIdsArr}) async {
var docId = '';
await chat.where('User ids', isEqualTo: userIdsArr).get().then((value) {
value.docs.forEach((element) {
docId = element.id;
});
});
//print(docId);
return docId
}
this returns the correct record, however, I think this is a terrible way of quering the database because I have to fetch all the records everytime.
Is there a way to write this so that I get the doc Id of the matching condition?
Unfortunately, there is not a better way to accomplish this. When you use the where clause though, it won't fetch everything like you suspect, only records that contain the value you are querying for. I don't believe it's as expensive of a call as you might think.
I need to get list of collection like
datalist = ["2009" , "2010"]
I can use this code to print what inside the 2009 , but that not i want
final _fireStore = FirebaseFirestore.instance;
Future<void> getData() async {
// Get docs from collection reference
QuerySnapshot querySnapshot =
await _fireStore.collection('data/student_details/2009').get();
// Get data from docs and convert map to List
final allData = querySnapshot.docs.map((doc) => doc.data()).toList();
//for a specific field
print(allData);
}
and I need to know about can I filter it
Thank you.
My Firebase view
In Firebase you can not fetch a list of Collections, You have to explicitly mention the name of Collection to fetch it. It means you must have pre-knowledge of name of Collection to fetch it.
I am building an Appointment Booking application want to retrieve all my documents from firestore at once on a button click. I used this:
Future<void> userAppointmentHistory() async {
String collectionName =
FirebaseAuth.instance.currentUser?.displayName as String;
String doc_id = "YyWqd9VlB1IdmYoIIFTq";
await FirebaseFirestore.instance
.collection(collectionName)
.doc(doc_id)
.snapshots()
.listen(
(event) {
print(
event.get("selectedDate"),
);
},
);
}
From the above code, I am getting only the specified document id details. So please help me modify the above code so that I get all the document details as I want to display these details on cards as my booked appointment history.
Here you are passing the doc id String doc_id = "YyWqd9VlB1IdmYoIIFTq";
You don't want to pass that if you want the full documents.
just pass the collection reference.
Follow the below code
fetchData() {
CollectionReference collectionReference =
FirebaseFirestore.instance.collection(collectionName);
collectionReference.snapshots().listen((snapshot) {
setState(() {
document = snapshot.docs;
});
print(document.toString);
});
}
Rudransh Singh Mahra,
It's as easy as putting text widget in our application.
Solution
You did it in right way but by mistake you have passed a specific id of documents in doc() as doc('YyWqd9VlB1IdmYoIIFTq'). you just need to remove that id from there and you may get your desired output.
What actually happens :
In your query you pass specific docId. So that it will returns that specified id document from your collection. To get all the documents from that collection you just need to do as follows,
Future<void> userAppointmentHistory() async {
String collectionName =
FirebaseAuth.instance.currentUser?.displayName as String;
// String doc_id = "YyWqd9VlB1IdmYoIIFTq";
await FirebaseFirestore.instance.collection(collectionName).doc().get()
}
And you will get your desired output if collectionName is valid and exist in firestorm database.
I tried with different ways but i can't edit the structure of code
//First way
QuerySnapshot querySnapshot = await db.firestoreInstance.collection('user-history').get();
var list = querySnapshot.docs;
print('MY LIST ===== $list');
//Second way
final CollectionReference collectionRef = db.firestoreInstance
.collection(historyCollection);
print('MY SECOND LIST ===== $list');
collectionRef.get().then((qs) {
qs.docs.forEach((element) {
print('MY doc id ${element.id}');
});
});
In my firebase collection(historyCollection) i have four documents but the debugger returns me empty array []. Is there another way to call all documents in certain collection through flutter?
I'm trying to call this method through FutureBuilder component.
My version of firestore is: "cloud_firestore: ^0.16.0+1"
This should do the trick:
Future<List<dynamic>> getCollection(CollectionReference collection) async {
try {
QuerySnapshot snapshot = await collection.get();
List<dynamic> result = snapshot.docs.map((doc) => doc.data()).toList();
return result;
} catch (error) {
print(error);
return null;
}
}
The entire problem was not from these fragments of code. This problem is came out from this that my collections have subcollections. I read about this and i understand that subcollections can live without their ancestors and the only way to access parents is to do this is directly specify the exact path and name of the document. To work this code in my case was needed to add dummy components of my entire set of collections. For more information please look up these two topics:
-> https://firebase.google.com/docs/firestore/using-console
-> Firestore DB - documents shown in italics