Firestore update document without skipping values in Flutter-CodePudding

Currently I have a collection with a list of Users in it

In my admin app I have a button that lets me update users documents based on the current value I set which is done via this function:

onPressed: () async {
  var querySnapshots = await collection
      .where('current_pick', isEqualTo: _currentValue)
      .get();
  for (var doc in querySnapshots.docs) {
    await doc.reference.update({
      'current_streak': FieldValue.increment(1),
      'current_score': FieldValue.increment(1),
      'rank_up': true,
    });
  }
},

The function works but it updates all the values one by one, which is fine at the moment but not so sure as the user count rises

What I have noticed that very rarely it skips updating one out of three values on some users and was wondering if there is a different approach on updating values without failure ?

CodePudding user response：

It sounds like you'll want to use a batched write, which allows you to write to multiple document atomically.

For your code that'd look something like this:

// Get a new write batch
final batch = db.batch();

// Put the updates into the batch
for (var doc in querySnapshots.docs) {
  batch.update(doc.reference, {
    'current_streak': FieldValue.increment(1),
    'current_score': FieldValue.increment(1),
    'rank_up': true,
  });
}

// Commit the batch
batch.commit().then((_) {

Note that a batched write can contain up to 500 operations, so if you may have more than 500 documents to update, you'll have to split it out over multiple batched writes.