in firestore/android/FirestoreSnippetsCpp/app/src/main/cpp/snippets.cpp [547:575]
void ReadDataGetMultipleDocumentsFromCollection(
firebase::firestore::Firestore* db) {
using firebase::Future;
using firebase::firestore::DocumentSnapshot;
using firebase::firestore::Error;
using firebase::firestore::FieldValue;
using firebase::firestore::QuerySnapshot;
// You can also retrieve multiple documents with one request by querying
// documents in a collection. For example, you can use Where() to query for
// all of the documents that meet a certain condition, then use Get() to
// retrieve the results:
// [START get_multiple]
db->Collection("cities")
.WhereEqualTo("capital", FieldValue::Boolean(true))
.Get()
.OnCompletion([](const Future<QuerySnapshot>& future) {
if (future.error() == Error::kErrorOk) {
for (const DocumentSnapshot& document :
future.result()->documents()) {
std::cout << document << std::endl;
}
} else {
std::cout << "Error getting documents: " << future.error_message()
<< std::endl;
}
});
// [END get_multiple]
}