I need to just check if user email exist in user collection or not. Right now I am doing like this
var check = await FirebaseFirestore.instance.collection('users')
.where('email', isEqualTo: userData['email']).snapshots();
But when I print check its showing
Instance of '_MapStream<QuerySnapshotPlatform, QuerySnapshot<Map<String, dynamic>>>'
How can I check that email exist in that collection or not ? Thanks 😊
Your check variable is a QuerySnapshot object, while you seem to want it to be a boolean that indicates whether the query had any results.
To get that:
var query = FirebaseFirestore.instance.collection('users')
.where('email', isEqualTo: userData['email']).limit(1);
var snapshot = await query.snapshots();
var check = query.size > 0;
Note that I also added a limit(1) to the query, since you never need to read more than one document to determine if any matches exist.
you can try or take reference form this method let me know if this solves your problem
static Future<bool> emailCheck(String email) async {
bool result = false;
QuerySnapshot snapshot = await
FirebaseFirestore.instance.collection('Users').get();
snapshot.docs.forEach((f) {
if (f['email'] ==email) {
result =true;
}
});
return result;
}
Related
I'm trying to run a query that retrieves a single row given a where clause and updates it. I understand that Firebase doesn't support an UpdateWhere operations so I'm trying to use a Transaction instead.
I'm having difficulty making it work, maybe I'm too used to sql dbs... Here's my broken code
try {
final whereQuery = _db
.doc(userPath(user))
.collection("someInnerCollection")
.where("active", isEqualTo: true)
.limit(1);
await _db.runTransaction((transaction) async {
final entry = await transaction.get(whereQuery); // This doesn't compile as .get doesn't take in a query
await transaction.update(entry, {
"someValue": "newValue",
});
});
} catch (e) {
...
}
From the test I’ve made, I would suggest the following to achieve what you mention:
Based on the following answer:
As you can see from the API documentation, where() returns a Query object. It's not a DocumentReference.
Even if you think that a query will only return one document, you still have to write code to deal with the fact that it could return zero or more documents in a QuerySnapshot object. I suggest reviewing the documentation on queries to see examples.
After doing the query consult, you have to get the DocumentReference for that given result.
Then, you can use that reference to update the field inside a Batched writes
try {
final post = await firestore
.collection('someInnerCollection')
.where('active', isEqualTo: true)
.limit(1)
.get()
.then((QuerySnapshot snapshot) {
//Here we get the document reference and return to the post variable.
return snapshot.docs[0].reference;
});
var batch = firestore.batch();
//Updates the field value, using post as document reference
batch.update(post, { 'someValue': 'newValue' });
batch.commit();
} catch (e) {
print(e);
}
You are passing the DocumentSnapshot back in the update() operation instead of DocumentReference itself. Try refactoring the like this:
final docRefToUpdate = _db.collection("colName").doc("docId");
await _db.runTransaction((transaction) async {
final entry = await transaction.get() // <-- DocRef of document to update in get() here
await transaction.update(docRefToUpdate, {
// Pass the DocumentReference here ^^
"someValue": "newValue",
});
});
You can use a collection reference and then update single fields using .update().
final CollectionReference collectionReference = FirebaseFirestore.instance.collection('users');
await collectionReference.doc(user.uid).collection('yourNewCollection').doc('yourDocumentInsideNestedCollection').update({
'singleField': 'whatever you want,
});
Same code using "where"
collectionReference.doc(user.uid).collection('yourNewCollection').doc().where('singleField', isEqualTo: yourValue).update({
'singleField': 'whatever you want,
});
I am working to build an admin access to a client. Among the visibility I need to constraint is the visibility of the button.
When changing access to user to admin, the button is not appearing back. The dependent boolean condition is mentioned below.
bool _show = false;
void showFloationButton() {
setState(() {
_show = true;
});
}
void hideFloationButton() {
setState(() {
_show = false;
});
}
void userAdminAccess() async {
FirebaseUser currentUser = await FirebaseAuth.instance.currentUser();
if ( currentUser != null) {
Firestore.instance
.collection('Users')
.where('isAdmin', isEqualTo: true);
} return showFloationButton();
}
Your code looks like it wants to perform a query, but it is not actually doing so. It's just building a Query object. You have to use get() to actually make that query happen, and await the response:
var querySnapshot = await Firestore.instance
.collection('Users')
.where('isAdmin', isEqualTo: true)
.get();
if (querySnapshot.size > 0) {
// there is at least one document returned by this query
}
else {
// there are not matching documents
}
I suggest learning more about how to perform queries in the documentation.
Note that what you're doing is potentially very expensive. It seems to me that you should probably get a single document for the user, identified by their UID, and look for a field within that document. Getting all admins could incur a lot of reads unnecessarily.
In my flutter firebase app, I am able to get the length of a user's activity document in firebase using a query snapshot. However, I want the number of documents to update in real-time without the user needing to refresh the page. Can I do that by converting the codes below using stream builder to get the real-time length and how can I do that?
this is the code am using now which works perfectly well but doesn't update in real-time.
//this is the code I want to convert to stream
//builder.
static Future<int> numActivities(String userId)
async {
QuerySnapshot userActivitiesSnapshot = await
activitiesRef
.document(userId)
.collection('userActivities')
.where('seen', isEqualTo: '')
.getDocuments();
return userActivitiesSnapshot.documents.length;
}
You need to use the docs property, which "returns a List containing DocumentSnapshot classes", as follows:
return userActivitiesSnapshot.docs.length;
To get a stream of documents, you need to use the .snapshots() method which returns a Stream of QuerySnapshot instead of the .getDocuments() (deprecated in favor of .get()) method which returns a Future of QuerySnapshot.
Then you can map Stream<Snapshot> into a stream of the length of the snapshot's documents.
Your numActivities method should look like this:
static Stream<int> numActivities(String userId) {
return activitiesRef
.document(userId)
.collection('userActivities')
.where('seen', isEqualTo: '')
.snapshots()
.map((documentSnapshot) => documentSnapshot.docs.length);
}
Using this in your use case, you need to listen to the stream and update the _activityCount variable.
_setUpactivityCount() async {
final String currentUserId =
Provider.of<UserData>(context, listen: false).currentUserId;
DatabaseService.numActivities(currentUserId).listen((activityCount) {
if (mounted) {
setState(() {
_activityCount = activityCount;
});
}
});
}
Make sure you take care of _activityCount being null in it's initial state.
I have a function which i created to query firestore and checkwhether a phoneNo exist in the collection called 'users'
I want to get a boolean if the phone No already exist in a document field.
How can i do it
Future<bool> phoneRegisterCheck(phone) async{
bool phoneAlreadyRegistered;
print('start');
var result = Firebase.instance.collection('users').where('phoneNo', isEqualTo: phone);
}
I want to wait for the query to finish and then return the result.
When i Use listen method it is not happening right function returns null.
Future<bool> phoneRegisterCheck(phone) async{
bool phoneRegistered;
print('start');
var result = DatabaseService().userCollection.where('phoneNo', isEqualTo: phone);
result.snapshots().listen((val){
val.documents.isEmpty ? phoneRegistered=false:phoneRegistered=true;
});
return phoneRegistered;
}
Since streams are asynchronous then in your code the return statement will be executed before the data is fully retrieved therefore you get null. You should
use await for instead of listen:
Future<bool> phoneRegisterCheck(phone) async{
bool phoneRegistered;
print('start');
var result = DatabaseService().userCollection.where('phoneNo', isEqualTo: phone).snapshots();
await for(var values in result){
values.documents.isEmpty ? phoneRegistered=false:phoneRegistered=true;
}
return phoneRegistered;
}
From the docs:
Streams can be created in many ways, which is a topic for another article, but they can all be used in the same way: the asynchronous for loop (commonly just called await for) iterates over the events of a stream like the for loop iterates over an Iterable.
https://dart.dev/tutorials/language/streams
I want to add data into the firestore database if the document ID doesn't already exists.
What I've tried so far:
// varuId == the ID that is set to the document when created
var firestore = Firestore.instance;
if (firestore.collection("posts").document().documentID == varuId) {
return AlertDialog(
content: Text("Object already exist"),
actions: <Widget>[
FlatButton(
child: Text("OK"),
onPressed: () {}
)
],
);
} else {
Navigator.of(context).pop();
//Adds data to the function creating the document
crudObj.addData({
'Vara': this.vara,
'Utgångsdatum': this.bastFore,
}, this.varuId).catchError((e) {
print(e);
});
}
The goal is to check all the documents ID in the database and see in any matches with the "varuId" variable. If it matches, the document won't be created. If it doesn't match, It should create a new document
You can use the get() method to get the Snapshot of the document and use the exists property on the snapshot to check whether the document exists or not.
An example:
final snapShot = await FirebaseFirestore.instance
.collection('posts')
.doc(docId) // varuId in your case
.get();
if (snapShot == null || !snapShot.exists) {
// Document with id == varuId doesn't exist.
// You can add data to Firebase Firestore here
}
Use the exists method on the snapshot:
final snapShot = await FirebaseFirestore.instance.collection('posts').doc(varuId).get();
if (snapShot.exists){
// Document already exists
}
else{
// Document doesn't exist
}
To check if document exists in Firestore. Trick is to use .exists method
FirebaseFirestore.instance.doc('collection/$docId').get().then((onValue){
onValue.exists ? // exists : // does not exist ;
});
I know this is a flutter firestore topic but I just want to share my answer.
I am using Vue and I am also doing a validation if the id is already taken on firestore.
This is my solution as of firebase version 9.8.2
const load = async() => {
try {
const listRef = doc(db, 'list', watchLink.value);
let listSnapShot = await getDoc(listRef);
if(listSnapShot._document == null) {
await setDoc(doc(db, 'list', watchLink.value), {
listName: NameofTheList.value
});
throw Error('New list added');
}
else {
throw Error('List already Exist');
}
} catch (error) {
console.log(error.message);
}
}
load();
The watchLink.value is the ID that you want to check
Edit:
if you console.log(listSnapShot), the _document will be set to null if the id does not exist on firestore. See screenshot below
If it does not exist
If ID already exists
QuerySnapshot qs = await Firestore.instance.collection('posts').getDocuments();
qs.documents.forEach((DocumentSnapshot snap) {
snap.documentID == varuId;
});
getDocuments() fetches the documents for this query, you need to use that instead of document() which returns a DocumentReference with the provided path.
Querying firestore is async. You need to await its result, otherwise you will get Future, in this example Future<QuerySnapshot>. Later on, I'm getting DocumentSnapshots from List<DocumentSnapshots> (qs.documents), and for each snapshot, I check their documentID with the varuId.
So the steps are, querying the firestore, await its result, loop over the results. Maybe you can call setState() on a variable like isIdMatched, and then use that in your if-else statement.
Edit: #Doug Stevenson is right, this method is costly, slow and probably eat up the battery because we're fetching all the documents to check documentId. Maybe you can try this:
DocumentReference qs =
Firestore.instance.collection('posts').document(varuId);
DocumentSnapshot snap = await qs.get();
print(snap.data == null ? 'notexists' : 'we have this doc')
The reason I'm doing null check on the data is, even if you put random strings inside document() method, it returns a document reference with that id.