We have a firestore collection, where each document has only one field names.
names contains a map.
Now if, I just want to update a single key value pair in that map, is there a way, other than:
await FirebaseFirestore.instance
.collection(namesCollectionName)
.doc(docId)
.update(savedNames.toJson())
.whenComplete(() => {developer.log("Update saved names success")})
.catchError((error) {
developer.log("Update saved names failed: $error");
throw Exception("Update saved names failed: $error");
});
This code updates the entire map.
I am not sure if there is a way to update just a key value pair. I felt it would be more efficient!
Firestore processes each entries in the map you pass as a set operation on that field.
If you want to update nested fields use . notation to mark that field. So say you store the full name for each user keyed on the Stack Overflow ID as a map under the names field, that'd be:
users
.doc('ABC123')
.update({'names.13076945': 'Nithin Sai'})
If your names field is an array and you want to add a certain name if it doesn't exist in there yet, that'd be an array-union, which looks like this:
users
.doc('ABC123')
.update({'names': FieldValue.arrayUnion(['Nithin Sai'])});
Related
I will pull data from firebase according to the search word, but I had a problem using "where", how can I solve it?
i want to filter by value under name
FirebaseFirestore.instance
.collection('tedaviler')
.where("value.name", arrayContains: name)
.snapshots()
this is not working
Firestore's array-contains operation tests whether the value that you pass exists as an item in the array you identify. The value you pass must match the complete item in the array, there is no option to check just some of the properties.
In your code you have a condition:
.where("value.name", arrayContains: name)
This means you're looking for a field value at the root of the document, and then a subfield name under that. But your value field is an array, and it doesn't have a subfield name. Each item in the array may have a name subfield, but that is not the same.
So the condition is never met, and your query returns no documents.
If you want to test the items in the value array, you will have to know the entire item. If you have that, the condition becomes:
.where("value", arrayContains: {
"id": "IzotonikId123",
"name": "IV Izotonik %1",
"price": 8.88
})
If you want to be able to search on just the names, you'll need to add another array field to the document, where you keep just the (unique) value names:
valueNames: ["IV Izotonik %1", "IV Izotonik %2", "IV Izotonik %3"]
Then you can query for the existing of a specific name with:
.where("valueNames", arrayContains: name)
name is not an array in your DB. It is a string. You should try
FirebaseFirestore.instance
.collection('tedaviler')
.where("value.name", isEqualTo: name)
.snapshots()
I am trying to query data from firestore and assign it to a List.
My users collection is as follows
List<String> emailList = ['Select email', 'email1', 'email2'];
I am trying to populate the above emaillist with the emails of persons such that the list is populated by emails of the persons where the groupId is equal to groupId of current user.
I tried querying by Firebase.instance.collection.where but it gets an error saying it cant be assigned to a List.
Any idea on how to do that?
It sounds like the issue is how you are adding to the list. You have to loop through the snapshot query and for each document, add to the list.
Firestore.instance.collection('users').getDocuments().then((snapshot) => {
snapshot.documents.forEach((doc) {
emailList.add(doc.data['email']);
})
});
Hope this helps!
I am trying to update or add to the end of the Lists that are in a Map and all inserted into a List that contains those maps. The List name is 'classes', what I have tried doing was using dot notation, so classes.index.example, but that doesn't work. Why...let's say I have two indexes in the list, If I go ahead and update index 0, the 'questions' and 'answers' will get inserted into that correct index, But for some reason, it will delete index 1 and any other that was created. It's as if It's overwriting all the data, but I don't understand why, I am not using 'setData()' Also, if I leave 'title' out, that too will get deleted??
Future updattingUserData(int index, List<dynamic> question, List<dynamic> answer, String title) async {
return await _collref.document(uid).updateData({
"classes.$index.questions": FieldValue.arrayUnion(question),
"classes.$index.answers": FieldValue.arrayUnion(answer),
//"classes.$index.title": title
});
}
Firestore doesn't have the capability of changing an array element knowing only its index within an array field. What you will have to do is read the document, modify the classes array in memory, then update the entire classes array field back to the document.
I'm experimenting with arrays and maps/objects in firestore. I wondered how can I remove a specific map from the array.
I tried something like this:
await Firestore.instance.collection('users').document(interestedInID).get().then((val){
return val.data['usersInterested'].removeWhere((item)=>
item['userID'] == userID
);
}).catchError((e){
print(e);
});
but I get this error in terminal:
Unsupported operation: Cannot remove from a fixed-length list
I don't really understand what it means. I did some googling and fixed-length list is exactly what it says. It's a list that has a fixed length and it can't be changed, but fixed-length list has to be declared explicitly. Growable list on the other hand doesn't need to be declared.
I haven't declared the fixed-length list in my firestore, yet it keeps saying that I can't remove elements from it. I can add / push elements however and remove them using:
'key': FieldValue.arrayRemove([value])
but I can't figure out how to remove the element based on a specific condition. In this case an userID.
Any suggestions?
Thanks a lot!
Figured it out.
await Firestore.instance.collection('users').document(interestedInID).updateData({
'usersInterested': FieldValue.arrayRemove([{}.remove(userID)])
});
I'm not sure, but I think get() simply allows you to read the document, but doesn't allow to make any changes to it.
Anyways, now it works
This may be a workaround:
You fetch your specific Array with key: values from Firebase
Put that in a temporary reference List in dart
Remove your specific Map from the reference List, like you did before
Update data in Firebase like so:
// make a reference List
List<Map> _modifiedUsersInterested = List();
// ... (fetch your Array first from Firebase, put those items in the reference List)
// remove the right Map from the reference List
_modifiedUsersInterested.removeWhere((item) => {
item['userID'] == userID
});
// set the reference List as your array in Firebase
await Firestore.instance
.collection('users')
.document(interestedInId)
.updateData(
{'usersInterested': _modifiedUsersInterested}
);
Here is a sample of my Firebase data:
I need to be able to search userFavorites for a given user (here, afaapy...) and return the results ordered by the values (timestamps) to get all the user's favorites in order of the date added to the database.
I can search by key as follows, and retrieve all favorites for the given user:
databaseRef.child("userFavorites").queryOrderedByKey().queryEqual(toValue: user.uid).observe(...)
But these favorties are ordered by their keys. If I try to order by value as follows, I get "Cannot use multiple queryOrderedBy calls!":
databaseRef.child("userFavorites").queryOrderedByKey().queryEqual(toValue: user.uid).queryOrderedByValue().observe(...)
How can I retrieve the favorites for a given user sorted by their value?
Second question: is there an easier way to retrieve data in the order it was added to the database?
You can't order the same ref multiple times as documented here
When you use a order or a filter method, it returns a Query Interface. See it as a filtered reference containing only a subset of the original data. It means that
databaseRef.child("userFavorites").orderByKey().equalTo(user.uid)
will not return userFavorite/${user.uid} but userFavorite filtered to show only the user.uid entry. You can see it by doing
databaseRef.child("userFavorites").orderByKey().equalTo(user.uid).ref.key
That should return 'userFavorites'
In your case, I see two options:
Keep going with orderByKey().equalTo() and sort the results yourself
Or use directly child() to get the user, then sort via Firebase (and don't forget to use the Firebase's snapshot.forEach to be sure you get the data in the query order):
databaseRef.child(`userFavorites/${user.uid}`).orderByValue().once('value', (snapshot) => {
if (snapshot.exists()) {
snapshot.forEach((child) => {
console.log(`${child.key}: ${child.val()}`)
})
}
})