I have two collections. One collection "User", who contains the user info (name...) And one collection "Post" who contains all posts of my flutter application. A post document contains many fields like a "Title", "Name" of the user. I add an option in my application to allow the user to change his name. But I must change the name in the "User" collection and in all posts it creates in the "Post" collection. How should I do it? Can anyone help me with an example?
There's nothing magical here. You'll need to get all post documents for that user with a query, and then update them one by one or in batches.
I'd also recommend checking out: What is the fastest way to write a lot of documents to Firestore?
Depends on which firestore are you using.
For Cloud Firestore:
You can update like this way, this is the case where you are updating just one field of your user.
final docRef = db.collection("users").doc("user_id");
final updates = <String, dynamic>{
"timestamp": FieldValue.serverTimestamp(),
};
docRef.update(updates).then(
(value) => print("DocumentSnapshot successfully updated!"),
onError: (e) => print("Error updating document $e"));
For updating a nested field:
// Assume the document contains:
// {
// Title: "Post Tittle",
// Name: "Post Name"
// user: { id: "1", name: "User Name" }
// date: "2022-12-08"
// }
db
.collection("posts")
.doc("post_id")
.update({"date": "2022-13-08", "user.name": "New name"});
You can see more details here: https://firebase.google.com/docs/firestore/manage-data/add-data
Assuming there is a user id attached to each post, you can query from the posts collection where the user (that is changing his/her name) id matches the id that is in the post (from the posts collection) and then modify the user property/attribute from the results.
A sample code would look like this,
To modify from the user collection
final docRef = FirebaseFirestore.instance
.collection('users')
.doc(id);
final response = await docRef
.update(updatedDateInJson)
.then((value) => value)
.onError((error, stackTrace) => error);
To modify from the posts collection where the user is found in a post
final response = FirebaseFirestore.instance
.collection('posts')
.where('name', isEqualTo: 'John')
.get()
.then((value) async {
// modify each doc
});
Quick Note: use a onError block to check for errors in updating docs.
Related
In my blogapp ,I am trying to implement comment system in flutter using cloud firestore. Each document is a post and I am trying to add comments as a subcollection to each document. How can I access each document id so that I can access the subcollection ?
Here I tried to print the document id below but it shows error NoSuchMethodError: 'id' method not found Receiver: null Arguments: [] :
final ref = await FirebaseFirestore.instance
.collection('blogs')
.add({
'title': titleController.text,
'body': myController.text,
'author': name,
'date': DateFormat('dd/MM/yyyy,hh:mm')
.format(DateTime.now()),
})
.then((value) => successAlert(context))
.catchError((error) =>
errorAlert(context));
titleController.clear();
myController.clear();
print(ref.id);
}
This is my firestore database :
You need to have access to the document id inside blogs, and access it's collection and the add your data like this...
await FirebaseFirestore.instance
.collection('blogs')
.doc(documentId) // you need to enter this document id
.collection('comments').add({
'title': titleController.text,
'body': myController.text,
'author': name,
'date': DateFormat('dd/MM/yyyy,hh:mm')
.format(DateTime.now()),
})
When you dont have the document id Firebase provides the get() command which returns the content of a collection. Like this:
db.collection("cities").get().then((res) => print("Successfully completed"), onError: (e) => print("Error completing: $e"));
But i realize that you will need the document id, so to get this you have to store the id after inserting a post, i've an example from a personal project:
await firestore.collection('item').add({
'quantity': element.quantity,
'product_id': element.product.productId,
}).then((value) {
/// Here you can access [value.id] to get this document id.
/// Now you can save it in a list or a class instance. Just keep it.
})
Now you can use the document id to update the post with a new comment, like this. For more information we have the Firestore documentation with flutter code snipets.
I’m working on an app with Flutter.
Each of my users has a map with their to-dos stored in cloud firestore:
I want to create a future that updates every to-do to false, which is true.
(In my example, that would be ’sport' and ’eat healthy')
My Problem:
I don’t really know how to do this. . .
I’d be very grateful if someone could help me.
You want to set every field inside the To-Dos map to false which is true. So I would suggest updating every field to false. You might think of checking if it is true and then updating it. But for your use case it is not a good option as anyway you want to set every field to false. Checking and then updating will only incur extra charges for querying. The following should work for your use case.
CollectionReference users = FirebaseFirestore.instance.collection('users');
Future<void> updateUserToDos() {
return users
.doc('your_document_id')
.update({
'To-Dos.Drink Water': false,
'To-Dos.Sport': false,
'To-Dos.eat healthy': false
})
.then((value) => print("User To-Dos Updated"))
.catchError((error) => print("Failed to update user: $error"));
}
To know more about updating document fields of Firestore in Flutter you can refer to this document.
EDIT
So you don’t know which fields are there inside the To-Dos map and you need to update every field inside the To-Dos map to be false. For that you can iterate over the keys of the map and update a new Map having keys same as that of the existing map and values to be false, then update the To-Dos Map field with the updated new Map. You can use the following piece of code. It will update every document inside the users collection.
FirebaseFirestore.instance
.collection('users')
.get()
.then((QuerySnapshot querySnapshot) {
querySnapshot.docs.forEach((doc) {
var updateMap = new Map();
var toDos = doc['To-Dos'];
for (var item in toDos.keys) {
updateMap[item] = false;
}
doc.reference.update({"To-Dos":updateMap });
});
});
To update the To-Dos map in any specific document you can do the following -
FirebaseFirestore.instance
.collection('users')
.doc("your_document_id")
.get()
.then((DocumentSnapshot doc) {
var updateMap = new Map();
var toDos = doc['To-Dos'];
for (var item in toDos.keys) {
updateMap[item] = false;
}
doc.reference.update({"To-Dos": updateMap});
});
There is no magic solution here. With your current data model, the only approach is to:
Read all documents
Change any false todo's to `true
Write back the document if you made any changes
The only way to make this cheaper (both in monetary cost as in the time it'll take) is to change #1 to only read documents that have a false value. In your current model that is only possible if To-Dos is an array, and then only for up to 10 values in there with an array-contains-any filter:
collectionRef.where("To-Dos", arrayContainsAny: [{
"Drink Water": false,
"Sport": false,
"eat healthy": false
}]
If the keys in this field are entered by the user, the above may become unfeasible because you can only have up to 10 values in there. The solution in that case would be to change your data model to fit your needs (as is quite common when working with NoSQL databases). For example, you could store a simple top-level hasUncompletedTasks field that you update each time you also write the document, and then use that for the query.
_getLatestCompletedWorkout() async {
try {
QuerySnapshot workouts;
workouts = await FirebaseFirestore.instance
.collection('users')
.doc(FirebaseAuth.instance.currentUser!.uid)
.collection('workouts')
.get();
for (var workout in workouts.docs) {
print('WORKOUT = ');
print(workout);
}
.....
What I really need is to get the last document saved; but before that I am just trying to fetch the "workouts" collection; the workouts.docs list always has 0 items. There are 2 items in the DB. What is wrong with this code? Also how to get the last saved item?
As mentioned by Frank :
You can refer Alex answer here :
The simplest way to achieve this is to add a date
property to each object in your collection, then simply query it
according to this new property descending and call limit(1) function.
This is the required query:
this.historyRef = afs.collection<History>('history', ref => ref.orderBy('date', 'desc').limit(1));
this.history = this.historyRef.snapshotChanges().map(actions => {
return actions.map(a => {
const data = a.payload.doc.data() as Hisotory;
const docId = a.payload.doc.id;
return { docId, ...data };
});
});
This has been found since cloud_firestore updates that prevent app that not regiter in App Check to take updates seriously "but it store it with lighter id color" which Protect your Cloud Firestore resources from abuse, such as billing fraud or phishing
Kindly check and ensure your app is registered inside App Check in Firebase console
I have created a database using Firestore. The main collection is "familyAccounts". Inside each account : you have info, and a subcollections of USERS (each account offers two Users (two differents user profiles), which have data too... So data is nested in various subcollections.
Here is how I "set" data in the database :
final _fireStore = FirebaseFirestore.instance;
//
if (newUser != null) {
_fireStore
.collection('familyAccounts')
.doc(email)
.set({
'name': '$name $firstName',
'country': country,
'region': region,
});
_fireStore
.collection('familyAccounts')
.doc(email)
.collection('users')
.doc('user1')
.set({
'userId': 'Utilisateur n°1',
'teacherCode': '',
'avatar': 'icons/avatar.jpg',
'vocLists': [],
});
_fireStore
.collection('familyAccounts')
.doc(email)
.collection('users')
.doc('user2')
.set({
'userId': 'Utilisateur n°2',
'teacherCode': '',
'avatar': 'icons/avatar.jpg',
'vocLists': [],
});
This works fine. But now, no matter what I try, I just do not understand how to retrieve this data. It was so easy to add it to the database. I have been reading online and am totally lost.
To make it as clear as possible : when the user logs in the app : he/she types in email and password : if account info is correct (using firebase_auth (this works)) then, I want to retrieve the data for both users linked to the account. Once I get the data, I use Provider to make it accessible wherever it will be needed in the app.
Can someone Help ? Thanks in advance :)
So far : I have managed to do this : I have created a function :
final _fireStore = FirebaseFirestore.instance.collection('familyAccounts');
getUserById(String id) async {
final DocumentSnapshot doc = await _fireStore.doc(id).get();
print(doc.data());
print(doc.id);
print(doc.exists);
}
It gives me the "first level" of data... But how can I dig deeper...?
I have a couple of writes that I want to be done together.
So I used a write batch.
Since the write batch requires a document reference, I have been creating the document before that write batch operation.
DocumentReference accountHistoryDoc = await queryResult.reference.collection('accountHistory').add({});
This led to many empty documents. Since I'm still testing and debugging the app, I assume because of an exception after the creation of the document.
How can I make sure that an empty document isn't created in the case of failure?
I'm thinking of changing this line
wb.set(
accountHistoryDoc, // Change this line
{
'account': newAccount,
'serverTimestamp': FieldValue.serverTimestamp(),
'type': 'hisab',
},
);
to
wb.set(
await subscriberDoc.collection('accountHistory').add({}),// new line
{
'account': newAccount,
'serverTimestamp': FieldValue.serverTimestamp(),
'type': 'hisab',
},
);
Is this my thinking correct?
Rest of code:
QuerySnapshot query = await FirebaseFirestore.instance
.collection(CurrentUser.getCurrentUser().uid)
.where('mobile', isEqualTo: mobile)
.get();
QueryDocumentSnapshot queryResult = query.docs.first;
DocumentReference subscriberDoc = queryResult.reference;
DocumentReference accountHistoryDoc = await queryResult.reference.collection('accountHistory').add({}); // < -- new empty document here
WriteBatch wb = FirebaseFirestore.instance.batch();
// update the total account
wb.update(
subscriberDoc,
{
'totalAccount': subscriber.totalAccount + newAccount,
},
);
// add new document in account history
wb.set(
accountHistoryDoc,
await subscriberDoc.collection('accountHistory').add({}),
{
'account': newAccount,
'serverTimestamp': FieldValue.serverTimestamp(),
'type': 'hisab',
},
);
If you call CollectionReference.doc() without an argument, it generates a new unique DocumentReference without already creating that document in the database. You can then use this DocumentReference to create the new document inside the batched write.
Also see the documentation for the FlutterFire doc() method.