I am using this way to search for users in firestore database and I think that it is inefficient way , because it give unrelated results , for example if I type 'k' it give me results does not contain 'k' at all like the image below .
var query = firestore
.collection("users")
.where('name', isGreaterThanOrEqualTo: customer)
.get()
.asStream();
any suggestion please ?!
When you are using the following call:
.where('name', isGreaterThanOrEqualTo: customer)
It means that you are searching the database for the documents in which the "name" property holds a value that is greater than the one you are typing. In this particular case, both "Omar" and "Second Omar" are present in the result-set, since each one of them starts with a letter that is alphabetically ordered after "k". In fact, all capital letters are present in alphabetical order after the lower-case letters. Remember that the search is performed lexicographically.
If you are looking for a full-text search, please note that Firestore doesn't provide one. As #Dharmaraj mentioned in his comment, you should use a third-party solution. You can also find more info in my answer from the following posts:
Search by pattern on Cloud Firestore collection
Is it possible to use Algolia query in FirestoreRecyclerOptions?
Related
While I'm using the below query in Firestore, an error is coming:
Code:
query = database.collection("CustomerViews/Data/Post")
.whereGreaterThanOrEqualTo("postDate", startDate)
.whereLessThanOrEqualTo("postDate", endDate)
.orderBy("postViews", Query.Direction.DESCENDING)
.orderBy("postDate", Query.Direction.DESCENDING)
Error:
Invalid query. You have an inequality where filter (whereLessThan(), whereGreaterThan(), etc.) on field 'postDate'
and so you must also have 'postDate' as your first orderBy() field, but your first orderBy() is currently on field
'postViews' instead.
The error message is quite explicit about the error. You are using both "whereGreaterThan()" and "whereLessThan()" on the "postDate" field, but you aren't first ordering the results based on that field, hence that error. Please remember, that the order of the method calls in Firestore is very important. To solve this, please change your query to:
query = database.collection("CustomerViews/Data/Post")
.orderBy("postDate", Query.Direction.DESCENDING)
.whereGreaterThanOrEqualTo("postDate", startDate)
.whereLessThanOrEqualTo("postDate", endDate)
.orderBy("postViews", Query.Direction.DESCENDING)
And right after that, simply create the corresponding index. That's it.
Edit:
According to your first comment:
By using your code data is coming but "postViews" descending is not happening. Only postDate descending is coming.
Yes, the results will be returned descending according to "postDate". And if two or more elements will have the same "postDate", then only those results will be after that ordered descending according to "postViews". This is how Firestore works.
According to your second comment:
I want the "postViews" in descending order in given date ranges.
Cloud Firestore queries can only sort or filter range on a single field. What you are trying to achieve it's not possible, since you are trying to filter on "postDate" and then order on "postViews".
In the official documentation, there is an example on how not to do it:
Range filter and first orderBy on different fields
citiesRef.whereGreaterThan("population", 100000).orderBy("country"); //Invalid
According to your last comment:
I got the solution for my problem. I have added the below line before attaching the ArrayList to an adapter.
postArrayList.sortByDescending { it.PostViews }
Indeed it will work if you download all documents on the client and to the filtering there, but it will cost you one document read for each document you download.
Based on your sample code, you have an inequality wherein postDate should be initialized first before postViews as the error suggested. This is currently a restriction of orderBy() clause wherein your first ordering must be on the same field.
In addition to #Alex's answer, You may check the links below for similar scenarios
Firestore query order on field with filter on a different field
Firestore "Invalid query" - Am I using Indexing wrong?
Finally, here's a documentation for the limitations of order and limit data with Cloud Firestore.
I got the solution for my problem. I have added below line before attaching the arraylist to an adapter.
postArrayList.sortByDescending { it.PostViews }
I am trying to display images from Firebase's storage in my Android app inside a GridView.
I have done that, however, the images are displaying in an unknown order, and I have noticed that there is a 'Last modified' column inside Firebase's storage when I upload the images to it.
My question is: is there a way that I could sort the images inside the GridView in order to display them according to that date? (for example, the last one added, would have the latest 'Last modified' date and would be viewed first and such...)
This is my code:
val listRef : StorageReference = FirebaseStorage.getInstance().reference.child("images/posts/$userName")
val fileNameList: ArrayList<String> = ArrayList<String>()
listRef.listAll()
.addOnSuccessListener { it ->
it.items.forEach{
fileNameList.add(it.name)
}
gridView?.adapter = ImageRecyclerAdapter(activity, fileNameList,userName)
}
Note: the code is in Kotlin
I have looked everywhere and couldn't find anything that helps.
Any help is appreciated, thank you :)
According to the official documentation regarding StorageReference's listAll() method:
List all items (files) and prefixes (folders) under this StorageReference.
You might not be interested in listing folders within the reference you are pointing to.
That been said, the best option that you have is to store the URLs in a database. Such a database can be either Cloud Firestore or Firebase Realtime Database. This means that each object should have at least two fields, one for the actual URL and one for a timestamp. Please see in my answer from the following post how you can add a timestamp to Firestore:
ServerTimestamp is always null on Firebase Firestore
Is in Java, but you can simply convert it to Kotlin. Once you have all URLs in place, you can create a query and order the URLs according to the date. In Firebase Realtime Database the default order is ASCENDING, but below is how you can reverse the order:
How to arrange firebase database data in ascending or descending order?
While in Firestore, you can simply pass the desired direction to Query's orderBy(String field, Query.Direction direction) method.
I've been trying to find a query for almost 2 days now
I want to search id (current user id) from the document 4 fields (customer1,customer2,customer3,customer4)
Here is the firestore document picture
tried this query
final Query userQuery = collectionReference
.whereEqualTo("customer1",firebaseAuth.getInstance().getCurrentUser().getUid())
.whereEqualTo("customer2",firebaseAuth.getInstance().getCurrentUser().getUid())
.whereEqualTo("customer3",firebaseAuth.getInstance().getCurrentUser().getUid())
.whereEqualTo("customer4",firebaseAuth.getInstance().getCurrentUser().getUid());
but this only shows up if the current ID is present in all 4. Is there any easier way to do this.
You can do that by using a field that is an array containing the uids you want to test, and then applying array-contains on it. In your case:
In your case:
customer: [customer1, customer2, customer3, customer4]
collectionReference
.where("customer ", "array-contains", firebaseAuth.getInstance().getCurrentUser().getUid())
Firestore does not support logical OR queries among mulitple fields. So, what you're trying to do is not possible with a single query using the database structure you have now. You would have to perform multiple queries and merge the results in the client.
If you want to be able to use a single query, you will have to change your database. One option is to put all the customers into a single array field and use an array-contains query to find a customer in that field.
In my database:
-Users(Top level collection):
---user1(doc):
----------pets(sub collection):
--------------pet1(doc)
--------------pet2(doc)
---user2(doc):
----------pets(sub collection):
--------------pet3(doc)
--------------pet4(doc)
If i have a List of ids: list("pet2", "pet3", "pet4)
Is there a way to do something like this and get a back a List of DocumentsSnapshots?
firestore.collectionGruop("pets")whereIn(FieldPath.documentId(), list)
It works with a root collection but i dont know if this is possible with a collection group
A collection group query is the only place where a filter on FieldPath.documentId() does not work the way you expect. That's because of some details about the way that this token actually works. If you try to this anyway, you will get an error like this:
Invalid query. When querying a collection group by FieldPath.documentId(), the value provided must result in a valid document path, but 'x' is not because it has an odd number of segments.
If you want to do a filter on document IDs in a collection group query, you will need to store the ID of the document as the value of a field in each document. If you use the field called "id", then you can filter on that field like this:
firestore
.collectionGruop("pets")
.whereIn('id', list)
This will give you a different error saying that you need to create an index, and give you a link to do so. After you create that index (it might take some time), you should be good to go.
See also: How to perform collection group query using document ID in Cloud Firestore
This question already has an answer here:
Firebase query if child of child contains a value
(1 answer)
Closed 3 years ago.
I need a firebase query to filter the list based on the value of an array.
if any of the index of GID(Array) contains the given key. e.g my key is YsGMyfLSGRNHxDWQmhpuPRqtxlq1 and one node's GID have that on 0th index and other have that on 1st index. So these two lists need to be returned.
Currently, I can only get the one at 0th index using the code
//userID = YsGMyfLSGRNHxDWQmhpuPRqtxlq1
firebaseDatabase.child("Groups").queryOrdered(byChild: "GID/0").queryEqual(toValue:userID)
When I try to combine the query I am getting errors.
I don't know about your database structure, But I can explain that There is a limitation in Firebase Realtime database that you can only order by 1 child.
So now if we require to order by 2 Childs we can combine 2 nodes and make it 1 node and can apply order by query on it. For example
If we have username & email fields we can make a new field username_email and can apply order by on it.
Like
user: {
username: "john",
email: "john#g.com"
username_email = "john_john#g.com"
}
Now we can write
firebaseDatabase.child("user").queryOrdered(byChild: "username_email").queryEqual(toValue: "john_john#g.com");
There is no way you can filter your groups based on a value that exist within an array. If you want to query your database to get all groups a particular user is apart of, then you should consider augmenting your data structure to allow a reverse lookup. This means that you should add under each user object the groups in which that user is present.
This means that you'll need to duplicate some data, but this is not a problem when it comes to Firebase. This is a quite common practice, which is named denormalization and for that, I recommend you see this video, Denormalization is normal with the Firebase Database.
When you are duplicating data, there is one thing that need to keep in mind. In the same way you are adding data, you need to maintain it. With other words, if you want to update/detele an item, you need to do it in every place that it exists.
However, what you need is actually allowed in Cloud Firestore. Its array-contains operator allow you to filter documents that have a certain value in an array. For more on this topic, please see the following post:
Better Arrays in Cloud Firestore.