使用 flutter 中的邀请码加入房间

Question

I'm trying to create a simple game application using flutter. It has a page where users can enter an invite code and press a button to join the room. I have multiple rooms with different names on firebase and each one has a unique inviteCode. How can I write a function to check through all the rooms if the enteredCode matches any of the rooms' invite codes?

This is what I've tried so far:

Future<bool> _checkInviteCode(String enteredCode) async {
    // reference to the Firestore
    final firestore = FirebaseFirestore.instance;
    //get the invite code collection
    final querySnapshot = await firestore.collectionGroup('inviteCode').get();

    // check if the entered code matches any of the invite codes in the Firestore collection
    if (querySnapshot.docs
        .any((doc) => doc.data()['inviteCode'] == enteredCode)) {
      print("Code matched!");
      return true;
    } else {
      print("Invalid code");
    }
    return false;
  }

Answer 1

There is no way in the Firestore API to query across multiple collections with different names. The only options are to query a single collection, or to query all collections with one name using a collection group query .

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So you will either have to query each collection (name) individually and merge the results in your application code, or you'll have to adapt your data model to fit the use-case (which is quite common in NoSQL databases).

For example, consider creating a collection inviteCodes where you (also) store the codes using the invite code as the document ID and then include a field that points to the document path for the user (or whatever document type you have) that holds that invite code. Having such a table would not only make this use-case simpler, but it will also immediately ensure that only one user can hold each invite code.