I have a collection "Tasks" that include some fields : The user that added the task, the name of the task, the category and I want to add another one with the steps of the task. Do I have an option to add a "Steps" field (and not collection!), and in this field I will have all the steps of the task?
Here the image of my firestore structure : Firestore structure
Of course, just use update
collection('Tasks').doc(docId).update({"steps" : "yourSteps"})
yourSteps here can be a string, int, list, a whole new map, anything. Without affecting the other fields in your document like category.
Important note:
.set() can also merge new data into the existing document if you pass the merge options:
.set(data, {merge: true})
.set() will write to the document if it exists, and will create a new document if it does NOT exist - with the mergeOption, it can merge in new fields or update selected ones.
.update() is similar, BUT if the document does not exist .update() will FAIL..
https://firebase.google.com/docs/reference/js/firebase.firestore.DocumentReference#set
Related
im trying to make a sort of chat app with the following architecture:
Its currently working as follows: in a root doc, there is an array of chat objects. Each chat object spawns a message doc, which contains an array of message objects. Same logic for comments.
Im thinking about a function to update all posts relative to the associated user, IE if a user changes their name all associated comments will be updated. Is this possible with the WhereIn() function? Or should i edit the architecture to something more like each document being its own message/comment? Thanks!
An in clause checks if a specific field is equal to one of a set of values, which doesn't apply here.
You might be thinking of array-contains, but that wouldn't work in your current structure either. The array-contains only matches exact an item in the array if it completely/exactly matches the value in the query.
The common way to allow such a query is to add a participants array field to each document where you store the UIDs of all participants in that doc. Then you can do an array-contains query against that.
Im trying to create one stream, that is using multiple documents references that are stored and fetched from Firebase Firestore.
Lets say I have two collection named users and documents. When user is created he gets document with his id in users collection with field named documentsHasAccessTo that is list of references to documents inside documents collection. It is important, that these documents can be located in different sub collections inside documents collection so I dont want to query whole documents and filter it, in order to save Firestore transfer and make it faster I already know paths to documents stored in documentsHasAccessTo field.
So for example, I can have user with data inside users/<user uid> document with documentsHasAccessTo field that stores 3 different document references.
I would like to achieve something like this (untested):
final userId = 'blablakfn1n21n4109';
final usersDocumentRef = FirebaseFirestore.instance.doc('users/$userId');
usersDocumentRef.snapshots().listen((snapshot) {
final references = snapshot.data()['documentsHasAccessTo'] as List<DocumentReference>;
final documentsStream = // create single query stream using all references from list
});
Keep in mind, that it would also be great, if this stream would update query if documentsHasAccessTo changes like in the example above, hence I used snapshots() on usersDocumentReferences rather than single get() fetch.
The more I think about this Im starting to believe this is simple impossible or theres a more simple and clean solution. Im open to anything.
You could use rxdart's switchMap and MergeStream:
usersDocumentRef.snapshots().switchMap((snapshot) {
final references = snapshot.data()['documentsHasAccessTo'] as List<DocumentReference>;
return MergeStream(references.map(ref) => /* do something that creates a stream */));
});
im working on firebase and im trying to update the document name and its field name together like shown in the image. i want them to be updated together.
i used this code
EditCourse(String cName, String newName) async {
var collection = FirebaseFirestore.instance.collection("Courses")
..where("Course name", isEqualTo: cName);
collection.doc(cName).update({'Course name': newName});
}
Answer:
As of Now Firebase not allows to update documents ids)
Suggestion:
You should use relational ids or random ids
(relational ids means suppose you have seller favorite collection you can give documents ids to movie/food ids)
There is no way to update the document ID of an existing document. If changing course names is a use-case you need to support, consider using Firestore's built-in ID generation when adding your documents (so add documents using the add() method).
If you stick to your current model, you'll have to:
Read the existing document.
Write the date under the new ID.
Delete the original document.
Given the type of operation, you'll probably want to use a transaction for that.
What if some data is already there inside the users collection ?
Would doing this 👇🏻 will delete all the previous data ?
var messageRef = db.collection('users').doc(userID)
.collection('private_user_data').doc(userID);
I want to add new data inside users collection and inside that a doc with 4 fields and one more collection inside that and inside that a doc with four more fields.
The code in your question doesn't read from or write to the database in any way. It merely sets up a reference to a document in the database.
There are few ways to implement this, depending on your exact use-case:
To merge data with an existing document, use the update method.
If the document may or may not exist, you can tell Firestore to merge the new values with the existing data when you call the set method.
If you want to set some fields only if the document doesn't exist yet, and leave them unmodified if the document already exists, you will need to use a transaction. In that case you may also want to make sure your security rules reject modifications to those initial fields.
With your code you don't make any operation on your db.
If you would know use .set(someData) your document would be created with given data if there is no document with given id or the document would be overwritten with the given data if there is a document with the given id.
Please check this post from the Firebase docs for more information.
EDIT
To create a document you have to do something like this:
var messageRef = db.collection('users').doc(userID)
.collection('private_user_data').doc(userID);
messageRef.set({
field1: input1,
field2: input2,
field3: input3,
field4: input4
})
Be aware that messageRef.set() will return a promise. So you have to deal with it. And here I would recommend you one of the tutorials from the Firebase team or one of many from the Internet.
Here is the schema for test db:
I want to write a query that can get all the documents where contacts have id=1 in any of the array index.
I have checked array_contains operator for firestore but the thing is my array have map which then have field id.
Thanks
You currently can't build a query that looks for an object field within an array. The only things you can find in an array are the entire contents of an array element, not a part of an element.
With NoSQL type databases, the usual practice is to structure you data in a way that suits your queries. So, in your case, you're going to have to structure your data to let you find documents where an array item contains a certain string. So, you could create another array that contains just the strings you want to query for. You will have make sure to keep these arrays up to date.
You could also reconsider the use of an array here. Arrays are good for positional data, but unless these contacts need to be stored in a certain order, you might want to instead store an object whose keys are the id, and whose field data also contains the id and name.
As Doug said, you can't query it,
but, if you could structure your data to something that looks like this
Store your data as a map
Use id as key and name as value
Now you can write a query that can get all the documents where contacts have id=1
db.collection("test").where("contacts.1", ">=", "").get()
If you have an array of maps or objects and want to get the docoments that contains this specific map/object like this ?
array_of_maps.png
you can use
queryForCategory(categName: string, categAlias: string): Observable[] {
firestore.collection('<Collection name>', ref =>
ref.where('categories',
"array-contains", {
"alias": categAlias,
"title": categName
}
One soulions is as #Doug said, to add array with the data you need to query, and keep it uptodate.
Another solution is to make contacts as sub collection of the document, an then you could make queries of the contacts and get its parrent.
final Query contacts = db.collectionGroup("contacts").whereEqualTo("id", 1);
for (DocumentSnapshot document : querySnapshot.get().getDocuments()) {
System.out.println(document.getId());
System.out.println(document.getString("parent_id"));
}
If you don't want to add parent as another field, you can get it from parent reference, check this answer https://stackoverflow.com/a/56223319/1278463
snapshot.getRef().getParent().getParent().collection("people")
https://firebase.google.com/docs/firestore/query-data/queries#collection-group-query