How can I list all documents in a firestore
FirebaseFirestore.instance
.collection('groups')
.doc('dialog')
.get()
.then((DocumentSnapshot documentSnapshot) {
if (documentSnapshot.exists) {
print('Document data: ${documentSnapshot.data()}');
} else {
print('Document does not exist on the database');
}
});
this code Always return to else
From the docs:
When you delete a document, Cloud Firestore does not automatically delete the documents within its subcollections. You can still access the subcollection documents by reference. For example, you can access the document at path /mycoll/mydoc/mysubcoll/mysubdoc even if you delete the ancestor document at /mycoll/mydoc.
Non-existent ancestor documents appear in the console, but they do not appear in query results and snapshots.
A document can exist even if one or more its ancestors don't exist. For example, the document at path /mycoll/mydoc/mysubcoll/mysubdoc can exist even if the ancestor document /mycoll/mydoc does not. The Cloud Firestore data viewer displays non-existent ancestor document as follows:
In a collection's list of documents, the document IDs of non-existent ancestor documents are italicized.
In a non-existent ancestor document's information panel, the data viewer points out that the document does not exist.
Since your document name is italicized, which means you either deleted the document or added the subcollection to an empty document which it seems you might have done according to your screenshot. Therefore to solve the issue delete the collection group and add the document with data:
FirebaseFirestore db = FirebaseFirestore.instance;
db.collection("group").doc("dialog").set({"name" : "peter"}).then((value){
db.collection("group").doc("dialog").collection("Tkxij").add({"test" :"test"});
});
Also queries are shallow, meaning if you are referencing a document then you will only get the data of that document, you won't get the data inside the subcollections.
I have added the code for your problem hope this clears your doubt, feel free to ask if you have any doubt.
getData( ) async{
final collectionData = await FirebaseFirestore.instance
.collection('groups').get();
//this forEach method will give every document of that collection
collectionData.docs.forEach((doc) {
final docData = doc.data();
final fieldData = docData['fieldName'];
});
}
Related
In the 1st screen shot there are many documents in collection users. Each documents contains further collection jobPost and that collection contains further documents and its meta data.
What I want here is go to the every document of collection users and further subcollection jobPost and fetch all the documents.
Suppose first it should go to document 1 in collection users, in the document 1 it should fetch all the documnets in subcollection jobPost then it should go to the 2nd document of collection users and then get all the documents in the subcollection jobPost and so on. what will be the query or implementation to this technique
What you're describing is known as a collection group query, which allows you to query all collections with a specific name. Unlike what the name suggests, you can actually read all documents from all subcollections named jobPost that way with:
FirebaseFirestore.instance.collectionGroup('jobPost').get()...
When performing a query, Firestore returns either a QuerySnapshot or a DocumentSnapshot.
A QuerySnapshot is returned from a collection query and allows you to inspect the collection.
To access the documents within a QuerySnapshot, call the docs property, which returns a List containing DocumentSnapshot classes.
But subcollection data are not included in document snapshots because Firestore queries are shallow. You have to make a new query using the subcollection name to get subcollection data.
FirebaseFirestore.instance
.collection('users')
.get()
.then((QuerySnapshot querySnapshot) {
querySnapshot.docs.forEach((doc) {
FirebaseFirestore.instance
.document(doc.id)
.collection("jobPost")
.get()
.then(...);
});
});
**
if you not have field in first collection document then its shows italic thats means its delte by default otherwise if you have field in first collection document then you can access it easily so this is the best way that i share
**
static Future<List<PostSrc>> getAllFeedPosts()async
{
List<PostSrc> allPosts = [];
var query= await FirebaseFirestore.instance.collection("posts").get();
for(var userdoc in query.docs)
{
QuerySnapshot feed = await FirebaseFirestore.instance.collection("posts")
.doc(userdoc.id).collection("userPosts").get();
for (var postDoc in feed.docs ) {
PostSrc post = PostSrc.fromDoc(postDoc);
allPosts.add(post);
}
}
return allPosts;
}
this is my function for deleting a document in my "files" collection
Future<void> deleteProgram(String id, String program) async {
try {
print(id + "----" + program);
await firestoreInstance.collection("files").doc(program).delete();
// await firestoreInstance.collection("programs").doc(id).delete();
print("done");
} catch (e) {
print(e);
}
}
program is the id of the document, when i use this nothing gets deleted, even if i hardcode the ID.
this is what my collection looks like:
as you can see, each document in the files collection also has a subcollection called files
what am i doing wrong here?
The only way to delete a collection is to delete each individual document from it. There is no atomic operation to delete a collection.
In your screenshot the opleiding4 is shown in italic, meaning that this document doesn't really exist, and the Firebase console merely shows that name to be able to show its files subcollection.
Once you delete all files from the /files/opeleiding4/files subcollection both that collection and its parent document will disappear from the Firebase console too.
Also see:
Firestore DB - documents shown in italics
How to recursively delete collection in firestore?
How to Delete all documents in collection in Firestore with Flutter
I have the following code with the objective of retring all the documents like this: Collection('A').document(currentUser), this should give me the document YRZ1**** as you may see in the first image. Now what I want to do is get all the documents in the t22o9*** subcollection, as showned on the second image, how can I do that?
var docPath=Firestore.instance.document('Messages/$currentUser');
docPath.snapshots().listen((event) {
print('Hello 12 ${event.data}');
});
In order to get data from subcollection you can do the following:
var db = Firestore.instance;
//This is a reference to the YRZ1**** doc
var messagesDoc = db.collection('Messages').document('Messages/$currentUser');
//collectionId is the t22o9*** id, you need to have this set previosly in your code
var docList = [];
messagesDoc.collection(collectionId)
.getDocuments()
.then((QuerySnapshot snapshot) {
snapshot.documents.forEach((doc) => docList.add(doc)'));
});
With this code, docList will be a list of the documents located at your subcollection t22o9*** of the YRZ1*** document.
Also you can check this link with some examples on how to get data from firestore using flutter.
EDIT:
As per what you have clarified on the comments, getting the subcollection data is a bit more complicated with subcollections that were created dynamically, as you can see on this link, which I assume is the case you have. The most feasible solution in your case would be to create a list of ids of subcollections in your parent document, so for example your YRZ1*** document would have this structure
document
id: YRZ1***
subCollectionIds : [subCollectionId1, subCollectionId2,...]
subCollection1
subCollection2
...
subCollectionN
Having this structure you could use this code to retrieve the list of subcollections and the first document of each subcollection, ordered by whatever field you'd like:
var db = Firestore.instance;
var listFirstDocSub = []
//This is a reference to the YRZ1**** doc
db.collection('Messages')
.document('Messages/$currentUser')
.getDocument()
.then((DocumentSnapshot doc) {
var listSubCollections = doc["subCollectionIds"];
listSubCollections.forEach((id) {
db.collection('Messages')
.document('Messages/$currentUser')
.collection(id)
.orderBy("WHATEVER_FIELD_YOU_DECIDE")
.limit(1)
.getDocuments()
.then((DocumentSnapshot snapshot) {
listFirstDocSub.add(snapshot);
})
});
});
NOTE: With this approach, everytime you add a new subcollection, you will also need to add it's id to the subCollectionIds list.
Hope This helps.
please how can I get all the value of my IndividualTaxData subcollection in Flutter.
First, you must get the reference to the parent document:
DocumentReference parentRef = Firestore.intances.collection('TaxData').document(taxDataId);
You can do the previous part with a direct reference to the document (like the code above) or with a query. Later, you must get the reference of the subcollection and the document that you get the information:
DocumentReference subRef = parentRef.collection('IndividualTaxData').document(individualTaxId);
And finally, get the data:
DocumentSnapshot docSnap = await subRef.get();
For you to return a simple document, you can use the following code for it.
var document = await Firestore.instance.collection('IndividualTaxData').document('<document_name>');
document.get() => then(function(document) {
print(document('character'));
// you can print other fields from your document
}
With the above code, you will reference your collection IndividualTaxData and then load it's data to a variable that you can print the values.
In case you want to retrieve all the documents from your collection, you can start using the below code.
final QuerySnapshot result = await Firestore.instance.collection('IndividualTaxData').getDocuments();
final List<DocumentSnapshot> documents = result.documents;
documents.forEach((data) => print(data));
// This print is just an example of it.
With this, you will load all your documents into a list that you iterate and print after - or that you can use with another method.
In addition to that, as future references, I would recommend you to check the following links as well.
Query a single document from Firestore in Flutter (cloud_firestore Plugin)
How to use Cloud Firestore with Flutter
Le me know if the information helped you!
I get some data from firestore. Sometimes when I called to get data, the collection is not created yet.
before calling get request, how do I check collection is exists or not?
Stream<List<ChatModel>> getChat(ChatFieldModel model) {
var ref = _db.collection('chats');
return ref
.document(model.docId)
.collection('messages')
.orderBy('timestamp', descending: true)
.snapshots()
.map((list) =>
list.documents.map((doc)=>ChatModel.fromForestore(doc)).toList());
}
I posted this before
final snapshot = await firestore.collection(roomName).getDocuments();
if (snapshot.documents.length == 0) {
//doesnt exist
}
Hope this helps
Collections are not created or deleted independently of documents. When you create a document and specify it as being part of a certain collection, that collection is created automatically if it does not already exist. Similarly, when you remove the last document in a collection, that collection will automatically be deleted. So there is really no circumstance where you need to worry about whether a collection has been created or not, and you have no explicit control over creating or deleting collections.
Usually a collection in Firestore gets deleted if no Documents exist in it.
However, there might be cases where you want to keep a history of the collection modification events, or let's say for some reason prevent Collections from being deleted.
Or for example, you want to know when a collection was created in the first place. Normally, if the Documents are deleted, and then the Collection gets created again, you will not know the initial creation date.
A workaround I can think of is the following:
Initialize each collection you want with a Document that will be specifically for keeping generic info about that collection.
For example:
This way, even if all other Documents in the Collection are deleted, you'll still keep the Collection in addition to some info that might be handy if In the future you need to get some history info about the Collection.
So to know if a Collection exists of no, you can run a query that checks for a field in Info Documents (eg CollectionInfo.exists) to know which Collections have been already created.
This is for the most recent update
final snapshot = await FirebaseFirestore.instance
.collection('collection name').get();
if ( snapshot.size == 0 ) {
print('it does not exist');
}
Feb 2022
Get QuerySnapshot and return querySnapshot.docs.isNotEmpty or isEmpty
Future<bool> isItems() async {
CollectionReference collectionReference =
_firestore.collection("users").doc(_user!.uid).collection("cart");
QuerySnapshot querySnapshot = await collectionReference.get();
return querySnapshot.docs.isNotEmpty;
}
await FirebaseFirestore.instance
.collection('collectionName')
.limit(1)
.get()
.then((snapshot) {
if (snapshot.size == 0) {
print("No collection");
}
});