Get array of ID from Firebase (DART/Flutter)

user_5223416 0
Viewed 1611

Is there any way to fetch data from Firebase with an array of documents. Now I do this with loop. It works but maybe there is some more efficient way to fetch data? Members list can contain up to 10k users so create 10k requests seems wrong.

Many thanks!

ref = db.collection('users');

  Future<List<User>> fetchAllMembers({List<dynamic> members}) async {
    List<User> results = [];

    for (String userID in members) {
      await ref.document(userID).get().then((result) {
        results.add(User.fromMap(result.data, result.documentID));
      });
    }

    return results;
  }
firebase dart flutter
2 Answers

SOLVED

So simple :). Working example below. Many thanks!

 final Firestore db = Firestore.instance;
 ref = db.collection('users');

List<dynamic> membersIDS = ['DSGSGSG', 'IBIOSCP3S', 'ASDUASDGU'];

  /// Fetch members list
  Future<List<User>> fetchAllMembers({List<dynamic> membersIDS}) async {

    /// With whereIn
    var result = await ref.where('uid', whereIn: members).getDocuments();
    var documents = result.documents.map((doc) => User.fromMap(doc.data, doc.documentID)).toList();
    return documents;

    /// With loop
    // List<User> results = [];
    // for (String userID in members) {
    //  await ref.document(userID).get().then((result) {
    //    results.add(User.fromMap(result.data, result.documentID));
    //  });
    // }
    // return results;
  }
user_52234160

Query documents where the given field matches any of the comparison values

userRef.where('id', 'in',
    [['DSGSGSG', 'IBIOSCP3S', 'ASDUASDGU']]);
user_127854900
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