How do I update data inside documents without spec

问题:

Is there a way to update data inside documents without specifying the document ID,

But while going thorugh stackoverflow I saw this code

firebase.firestore().collection("users")
  .where("name", "==", "Daniel")
  .get(function(querySnapshot) {
    querySnapshot.forEach(function(document) {
     document.ref.update({ ... }); 
    });
  });

Can someone please translate this to flutter code(Dart) please. It's a query to norrow down the document search without having to put in the document ID. I think.

回答1:

The Dart equivalent to code you posted would look like this:

Firestore.instance.collection('users')
  .where('name', isEqualTo: 'Daniel')
  .getDocuments()
  .then((querySnapshot) {
    querySnapshot.documents.forEach((documentSnapshot) {
      documentSnapshot.reference.update({ ... });
    });
  });