I have list of strings, and using not operator I wanted to select all values except one. But I couldn't find anything about not opertor in the firebase website. Please help me with this issue.
P.S: This Link explains how to do the inequality operation with numbers, and not strings
It's a limitation with Cloud Firestore queries. But I found a workaround.
Cloud Firestore Documentation states,
"Queries with a != clause. In this case, you should split the query into a greater-than query and a less-than query. For example, although the query clause where("age", "!=", "30") is not supported, you can get the same result set by combining two queries, one with the clause where("age", "<", "30") and one with the clause where("age", ">", 30)."
New update on Firestore now supports not equal and not in queries. As mentioned here:
const capitalNotFalseRes = await citiesRef.where('capital', '!=', false).get();
const notUsaOrJapan = await citiesRef.where('country', 'not-in', ['USA', 'Japan']).get();
Related
In the following code, I want to use multiple array-contains queries, which is inappropriate according to firebase limitations.
await firestore
.collection("collection")
.where("field1", "array-contains", value1)
.where("field2", "array-contains", value2)
.where("field3", "array-contains", value3)
.get();
Tried to find a workaround solution by adding all values to one array and query on that array but it seems firebase does not support array-contains-all query.
Any suggestion how can I reframe my query?
I am using this code to retrive data from firestore
querysnap = FirebaseFirestore.instance
.collection("datas")
.where("cat", whereIn: Cateogryarray )
.where("City", whereIn:Cityarray)
.snapshots();
Then I get this error.
You cannot use 'whereIn' filters more than once.
How can I execute this query.
As the Firestore documentation on query limitations says:
You can use at most one in, not-in, or array-contains-any clause per query. You can't combine these operators in the same query.
Since you're trying to use two in clauses in your query, Firestore gives an error.
The most common workaround is to run with one clause against the database (typically the one you expect to exclude most documents from the result), and perform the rest of the filtering in your application code.
Another idea is to get individual snapshots for each parameter that would need the inclause.
Then once you have each of your snapshots, do an intersection of the lists. This will return the results where every record adheres to each individual filter.
My query is:
snapshot = await FirebaseFirestore.instance
.collection('dialogs')
.where('active', isEqualTo: true)
.where('users', arrayContains: globals.user.userId)
.where('readers', whereNotIn: [globals.user.userId])
.orderBy('priority')
.limit(1)
.get();
I'm getting the above exception:
Unhandled Exception: [cloud_firestore/unknown] An error occurred while parsing query arguments, see native logs for more information.
I have found some notes on the official Firestore documentation:
You can use at most one in, not-in, or array-contains-any clause per query. You can't combine these operators in the same query.
You can't combine not-in with not equals !=.
All should be just fine in my case.
Also I have tried several things:
If I remove only the whereNotIn line, everything is just fine.
if I remove only the arrayContains line, everything is just fine.
Why am I getting a query parsing exception?
Thanks
TL;DR
Firestore query documentation was not up to date (relevant for 04.04.21).
More details
I have checked my android Logchats on android studio and found out that:
Invalid Query. You cannot use 'not_in' filters with 'array_contains' filters.
While firebase documentation says that:
You can use at most one in, not-in, or array-contains-any clause per query. You can't combine these operators in the same query.
It was not mentioned on the Firebase documentation that array-contains cannot be at the same query along with not-in.
Conclusion
If you are encountered with query parsing exception. The most updated and fastest way to get relevant information about the problem is to check your Logchats.
Firestore Limitation
Firebase firestore doesn't allow you to use whereNotIn and arrayContains in a single query. see here
SOLUTION
Split the query, first get entires by
snapshot = await FirebaseFirestore.instance
.collection('dialogs')
.where('active', isEqualTo: true)
.where('users', arrayContains: globals.user.userId)
//.where('readers', whereNotIn: [globals.user.userId]) <-- remove this
.orderBy('priority')
.limit(1)
.get();
Then filter the received snapshot locally ( say in a for loop )
Though it will work but bear in mind that this will be a performance hit. So, the best approach is to avoid such queries.
Hope this helps 🙂
This question already has answers here:
Firestore: how to perform a query with inequality / not equals
(7 answers)
Closed 3 years ago.
I am fetching a data from fire-store I have an order Object which have a status as an attribute that can be "pending"," delivering","delivered".
What I want to do is getting all the orders except the one with status "delivered"*.
How I can do that with Where clause ?
return _fs
.collection('orders')
// .where('status', ' ', 'delivered')
.where('deliveryTime', isGreaterThan: startTime)
.where('deliveryTime', isLessThan: endTime)
.snapshots();
any help will be appreciated
You can view the "Query limitations" section in the querying article:
Cloud Firestore does not support the following types of queries:
Queries with a != clause. In this case, you should split the query into a greater-than query and a less-than query. For example, although the query clause where("age", "!=", "30") is not supported, you can get the same result set by combining two queries, one with the clause where("age", "<", "30") and one with the clause where("age", ">", 30).
return _fs
.collection('orders')
.where('status', isGreaterThan: 'delivered')
.where('status', isLessThan: 'delivered')
.snapshots();
However
As you can see, I removed the range filter on deliveryTime because it is impossible to perform range filters on multiple fields as explained here:
You can only perform range comparisons (<, <=, >, >=) on a single field, and you can include at most one array-contains clause in a compound query[.]
The following query is returning results for ("flag","==","someFlag") as if the array_contains part of the query doesn't exist:
myRef
.collection('someCollection')
.where("flag","==","someFlag")
.where("folders","array_contains","test string")
.get()
My expectation was that this query would produce an error in the console with a link to create a composite index for the two fields in the query. I can create the index myself, but didn't want to do so without trying to fully understand what's going on.
EDIT:
This gibberish query has the same effect (returns results for "flag == someFlag"). Shouldn't it throw an error?
myRef
.collection('someCollection')
.where("flag","==","someFlag")
.where("asdf","asdf","asdf")
.get()
I make the assumption you are using the Web SDK. Note that the syntax is
.where("folders","array-contains","test string")
and not
.where("folders","array_contains","test string")