Firebase Firestore - OR query

Question

How to get data by multiple values of one field? For example, I have a database with posts and I want to query for all posts where blogId is 1 or 2, sorting by timestamp.

collection("posts").whereEqualTo("blogId", "1")
.whereEqualTo("blogId", 2).orderBy("timestamp", Query.Direction.DESCENDING).limit(50)

The code above is not working :(

How to achieve this? Regards :)

Answer 1

Firestore now supports "IN" queries for this purpose.

The query would look like this:

database.collection("collectionName").where("fieldName", "in", ["fieldValue1", "fieldValue2"]);

You can have up to 10 values (fieldValueX) to check "IN" of.

---

The code OP desired would be as follows:

database.collection("posts").where("blogId", "in", ["1", "2"]); 

Answer 2

You could combine the Observables and return as one

orQuery(){

    const $one = this.afs.collection("posts", ref => ref.where("blogId","==","1")).valueChanges();
    const $two = this.afs.collection("posts", ref => ref.where("blogId","==","2")).valueChanges();

    return combineLatest($one,$two).pipe(
        map(([one, two]) => [...one, ...two])
    )
}

getOr(){
    this.orQuery().subscribe(data => console.log(data))
}

Answer 3

Firebase has listened to our requests and they have included IN query from 7 Nov, 2019. It's a kind of OR query, where you can have upto 10 OR filters.

For android:

collection("posts").whereIn("blogId", Arrays.asList("1", "2"))
.orderBy("timestamp", Query.Direction.DESCENDING).limit(50);

Firebase documentation

Answer 4

OR operator is not accepted in firebase firestore:

Cloud Firestore provides limited support for logical OR queries. The in, and array-contains-any operators support a logical OR of up to 10 equality (==) or array-contains conditions on a single field. For other cases, create a separate query for each OR condition and merge the query results in your app.

Queries in Cloud Firestore, Query limitations

Normally using firebase syntax you can call two collections:

const res1 = async collection("posts", ref => ref.where('blogId', '==', 1).get();
const res2 = async collection("posts", ref => ref.where('blogId', '==', 2).get();

and you can merge the results before serving to the view.

But in this case where you have blogIds you can use this syntax: collection("posts").orderBy('blogId').startAt(1).endAt(2);

e.d

Answer 5

I couldn't find any documentation for the ability to OR together where conditions. But you can rephrase your requirement on the blogId as follows:

WHERE blogId > 0 AND blogId < 3

Try this code:

collection("posts")
.where("blogId", ">", "0")
.where("blogId", "<", "3")
.orderBy("timestamp", Query.Direction.DESCENDING)
.limit(50)

Answer 6

Firestore now supports OR queries (in preview) that might be useful if you want to perform an OR operation on multiple fields.. You can use it from Firebase SDK v24.4.5.

// Returns all documents with capital = true OR population > 1000000
Query query = collection.where(Filter.or(
        Filter.equalTo("capital", true),
        Filter.greaterThanOrEqualTo("population", 1000000)
));

Answer 7

For Android users, please note that Firestore supports now logical OR queries. So now, you can perform OR queries on multiple fields. The option is available starting with Cloud Firestore version 24.4.5.

In code, it will be as simple as:

val db = Firebase.firestore
val citiesRef = db.collection("cities")
val query = citiesRef.where(Filter.or(
        Filter.equalTo("capital", true),
        Filter.greaterThanOrEqualTo("population", 1000000)    
))

Which will return documents where the capital is set to true OR, documents where the population is greater than or equal to 1_000_000.

Answer 8

As of March 2023, Firestore supports native or queries: https://firebase.google.com/docs/firestore/query-data/queries#or_queries

An example they give is:

const q = query(citiesRef,  
  or(where('capital', '==', true),
     where('population', '>=', 1000000)
  )
);

Answer 9

Firestore has no OR queries. They way you'd do that is by running two queries and splicing them.

You could for example:

const search = ( key, value ) =>  collection( 'users' ).where( key, '==', value ).get().then( doc => doc.data() )

Promise.all( [ search( 'name', 'John' ), search( 'name', 'Johnny' ) ] )
.then( ( [ one, two ] ) => one.concat( two ) )
.then( allResults => dothings() )

Answer 10

For Android, I am using OR query like this.

List<String> values = new ArrayList<>();
    values.add("Value 1");
    values.add("Value 2");

and then use the .whereIn query like this.

db.collection("collectionName")
            .whereIn("fieldName", values)   // where values is the list we created
            .get()
            .addOnCompleteListener(new OnCompleteListener<QuerySnapshot>() {
                @Override
                public void onComplete(@NonNull Task<QuerySnapshot> task) {

                    if (task.isSuccessful()) {

                      // Do your stuff

                    }

                }
            });

Answer 11

Try this

collection("posts").start("blogId", "1")
.end("blogId", 2).orderBy("timestamp", Query.Direction.DESCENDING).limit(50)

Answer 12

You can use De Morgaan's laws to rewrite an AND query as an OR query.