const groupids = '0ab449e7-5d06-4f8c-9bb0-de87e7f3f684,fae2d5ac-a9f6-42c2-9a4c-20143e49b21b';
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mgt people picker is not fetching the users from the given group ids instead its fetching all the users. If i given hte attribue group-id and given the single group id its fetching the users from that group only but for multiple groups its not working
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I want to assign a unique but incremental document/record(a data entry, not Firebase document) number when user generates his/her document in the app.
The document number should be unique integer/long and will be visible on the generated PDF document of the user as Your document number : 1100xxxxxx. This last generate document's number will be stored separately so when a new user generated his/her document, this number can be easily picked, incremented and assigned to user.
This way I won't have to query the database again for the last generated number using sorting as
FirebaseFirestore rootRef = FirebaseFirestore.getInstance();
Query query = rootRef.collection("Users")
.orderBy("DocumentNo", Query.Direction.DESCENDING)
.limit(1);
Right now, I generate a user by assigning the user.uid to the Firebase document. The reason I want to ensure the uniqueness of generated certificate number is that it will be visible to user and multiple users will be hitting the server at the same time(same millisecond even).
Although, I've seen almost every similar answer but the answer I've found similar to what I was thinking is this. Also, this unanswered question is what I should do but it has problems too.
So, is there a way by which I can generate a unique document/record number to the user? Answer need not be in Flutter, I want the logic mainly.
If you want to increment a number every time something happens do:
document.ref.update({unique_value: FieldValue.increment(1)});
That number will be unique. It will work with multiple users hitting the server at the same time.
I am working in a small project that uses Firestore database as a backend. I explain about the database so it is understood what I need:
Basically I have a collection that contains a list of documents where each one of them represent a game. For each game I have the name, cover image, info, category, etc.
I also have a collection of the users, where I have the specific UID for each user (retrieved from the auth section), email, etc.
What I want now is to save the score that some user may have in some of these games, as well as the favorite games that the user could save. What I don't get to understand is how to create the connection between the users and the games. For example, I thought that I should save the users score creating a collection within each document(game) in the first collection that mentioned. But when I create this collection with ID "scores" it asks me for the first document where I have to facilitate an ID (if not automatic) and then I don't know how to proceed.
I have read also that I would have to create additional collections in the root folder like "favorites" or "scores" specifying the UID of the user but, how do I connect the user UID, the score, and game which the user got that score from?
I hope I explained myself properly. Thanks.
Firstly, I agree with Doug's comment above. The Firestore tutorial videos are a great resource!
In terms of connecting data to your user, you have some options. You can either:
Create sub-collections under each user. Such as /users/{user_id}/favorites. Favorites could be a sub-collection or an array of game_ids depending on your use case.
Store a userID field in the documents in a top level "scores" or "favorites" collection. Then you can query for scores in the /scores collection by adding a where userID == {user_id} clause to your query of the /scores collection.
I am building a social media database schema, in which I have users, followers, tags and posts. To conform to the firebase model I have flattened the structure as suggested in the firebase documentation as seen below. The issue that I am struggling with is when a user selects a tag and sees a bunch of posts from the tagPosts table all related by tag returned, I would then like to show the posts created by the current users followers first.
In SQL this would be done with an inline query checking the users followers, against the posts returned by a specific tag.
However in firebase I am not sure how do this without downloading all the posts contained under the tagID node in tagPosts and checking through each post's creator against the node of Followers for the current user userID. This operation could easily grow out of hand for 100s of posts amongst 100s of users. Ive tried modeling off of this answer, How do I check if a firebase database value exists? and this article From SQL to Firebase — How to structure the DB for a social network app. Am I poorly structuring the data how do I fix this thank you so much.
`
Users-
-userID1
-misc. userData
-userID2
-misc. userData
Followers-
-userID1
-userIDOfFollower1
-userIDOfFollower2
Following-
-userID1
-userIDOfFollower1
-userIDOfFollower2
Posts-
-postID1
-userIDFromCreator
-misc. PostData
Tags-
-tagID1
-misc. TagData
TagsUsers
-tagID1
-userID1
-userID2
TagsPosts
-tagID1
-postID1
-postID2
Edits-Thank you Frank
In our storyboard flow we plan to have a user see a wall of tags determined by constantly updating popular score based on properties of the tag and where we predict the user may have interest. The user will then select a tag and see posts related to that tag, from those posts I would like to show the posts from a users followers before those of everyone else who’s post falls in the category of a specified tag.
I have considered two possibilities either I optimize on reads in which I would have to keep track of every time a users follower posts to a tag and record the tagID along with the postID in a node for every follower a user has who posted in a special node of FollowersTags which would have a structure of listing for each userID a list of users and the all the followers of a user posted to which would become 100s of writes for each post created directly proportional to the number of followers a friend has.
*creates a list of posts to a specific tag made by followers
FollowersTags
-userID1_tagID1(composite key)
-postID1
-postID2
-postID3
-postID4
-userID1_tagID2
-postID1
-postID2
-postID3
-postID4
Or I could optimize on writes as tried above, which presents us with our current predicament of having to perform a query 100s of times directly proportional to the number of posts in a tag.
Is there any way around these two options which of the two is the better approach.
Unfortunately I would not be able to predict the posts displayed to the user before they select a tag.
In the Firebase Realtime Database, I typically model the data in the database to what I show on the screen. So if you have a "wall" of recent, relevant posts for each user, consider modeling precisely that in your database: a list of recent, relevant posts (or post IDs) for each user.
UserWalls
userID1
"timestamp_or_push_id": "postId1"
"timestamp_or_push_id": "postId2"
userID2
"timestamp_or_push_id": "postId1"
"timestamp_or_push_id": "postId3"
While the problem of determining what to show remains the same, with this database model it's now a write-time problem, instead of a read-time problem.
Am looking at the data structure in this post and want to know how you would go about getting the emails of users who belong to a certain group when they could belong to several groups and the GroupID stored against that user is the current group they are participating in?
Do you store the email addresses with the userid under the "members" or, instead, for each member of the group, get that user's email address from the "users" document userid (this would mean iterating through the group/members collection and doing a query for each user. Not very efficient).
Am used to SQL so this is all new to me.
You should have a single node for each user
/users/UID/emails/
/users/UID/emailunread/
/users/UID/settings/
/users/UID/details/
/users/UID/payments/
So you can simply do a subscription for a singular node path this.myDatasubscription = this.DB.list('users/' + this.uid).snapshotChanges() ensuring changes like new emails or account settings will detected and rolled out in real time back to the app, so your are using angular/ng or something similar client side then your variables {{this.email_list}} should update real time with no page changes.
Take a look at this one.
error: Property 'getChildren' does not exist on type 'DataSnapshot'
In Firebase database I have a list of Bookings.
Each Booking as the following structure
{
userUid: string,
status: string,
moreStuff: {
....
}
}
I need to select all the bookings associated to a certain user (i.e. whose userUid is equal to the uid of the user, which is known by by app) which have a certain status (e.g. status = confirmed).
I can select the Bookings belonging to a specific user using the following query
db.list('bookings', {
query: {
orderByChild: 'userUid',
equalTo: user.uid
}
})
but I have no idea if I can add the additional select condition e.g. status = confirmed
In a firebase query you can't filter on more than a single field. I have encountered this restriction many times.
I think your challenge would become easier if you model your data differently. I believe that you have a one to many relationship between Users and Bookings. That is, a user may have many bookings but a booking may only have one user. If this is the case, I would create a top level node "bookingLists" which contains separate booking list for each user. The structure is illustrated below. The path "bookingList/< userId >" contains the booking list for a given user. You can access the list if you know the userId. It will contain all bookings for that user. You can then query on a single field in each booking to filter by.
bookingLists
<userId>
bookings
<bookingKey>
status
...other fields
If you need to further filter the booking, you could filter on the client side using observable operations map and filter. This will scale, as long as, each user doesn't have too large a booking list.