Cloud Firstore Plugin Should Support Logical Or Query

[maheshj01]

Currently, we can do logical And operations using the where clause something like this

Logical AND

Firestore.instance.collection("messages")
    .where("field1", isEqualTo: "value1")
    .where("field2", isEqualTo: 'value2')

I would propose a similar functionality for logical OR

Proposal

Firestore.instance.collection("messages")
    .where("field1", isEqualTo: "value1")
    .orWhere("field1", isEqualTo: 'value2')

The current approach which works for me is using the CombineLatestStream from the rxdart package

Current Approach

final stream1 = Firestore.instance.collection("messages")
    .where("field1", isEqualTo: "value1");
final stream2 = Firestore.instance.collection("messages")
    .where("field1", isEqualTo: "value2");

StreamBuilder(
    stream: CombineLatestStream.list([
    stream0,
    stream1,
  ]),
builder: (context, snapshot) {
  final data0 = snapshot.data[0];
  final data1 = snapshot.data[1];
})

I am not sure how efficient the current approach is, or what are the technical challenges involved with adding support for Logical Or query to firestore plugin I would love to hear more about it. Feel free to close this issue if this is a duplicate or is not related.

[larssn]

You can already do that:

Firestore.instance.collection("messages")
    .where("field1", whereIn: ["value1", "value2"])

This is equivalent to your statement. It reads as "Find documents where field1's value is contained in the list of values (value1 and value2)".

You see some more examples here: https://firebase.googleblog.com/2019/11/cloud-firestore-now-supports-in-queries.html

Keep in mind that the Flutter plugin is limited to what the underlying Android/iOS/Web implementations support. It's a wrapper around those implementations.

[maheshj01]

Thanks

[maheshj01]

Update:

Originally posted here https://stackoverflow.com/a/76018163