Question 75988 in Flutter Question posted in
The official Flutter documentation can be found here.

How to retrieve data from Firestore in flutter

I have made a collection in this way:
var res = FirebaseFirestore.instance.collection("hotels");
var response =await res.doc(res.id).collection(data.email).doc(data.hotelName).collection(data.hotelName).doc().collection(‘hotel_details’).add( ‘hotel_name’: data.hotelName,
‘hotel_email’: data.email,});

This is the code to retrive I have used:
final res = FirebaseFirestore.instance.collection("hotels");
final response = await res.doc(res.id).collection(email).get();

I am getting empty list in response.docs

Tags:

2

Answers


  1. 0

    You need to use reference to retrieve the document in the future.

     var res = FirebaseFirestore.instance.collection("hotels");
 var docRef = res.doc(); // generates a new document reference with a unique ID
 var docId = docRef.id; // gets the ID of the new document reference    
 var data = {
  'hotel_name': data.hotelName,
  'hotel_email': data.email,
};
var response = await docRef.collection(data.email).doc(data.hotelName).collection(data.hotelName).doc(docId).set(data);

    Also to retrieve documents from the subcollection you should pass the document ID to the doc() method.

    final snapshot = await 
res.doc(docId).collection(data.email).get();
if (snapshot.docs.isNotEmpty) {
  snapshot.docs.forEach((doc) {
    print(doc.data());
  });
} else {
  print('No documents found');
}
    Login or Signup to reply.
  2. 0

    Based on your code and making it the required corrections, to add and retrieve data you could possibly do it following way.

    Add new hotel using set:

    final newHotel = <String, dynamic>{
'hotel_name': data.hotelName,
'hotel_email': data.email,
};

 FirebaseFirestore.instance
                  .collection('hotels')
                  .doc(docId)           
                  .collection(data.email)
                  .doc(data.hotelName)
                  .collection(data.hotelName)
                  .doc()
                  .set(newHotel)
                  .onError((e, _) => print("Error writing document: $e"));

    Retreive data using StreamBuilder:

     @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: Center(
        child: StreamBuilder<QuerySnapshot>(
          stream: .collection('hotels')
                  .doc(docId)           
                  .collection(data.email)
                  .doc(data.hotelName)
                  .collection(data.hotelName)
                  .snapshots(), 
          builder: (BuildContext context, AsyncSnapshot<QuerySnapshot> snapshot) {
            if (snapshot.hasError) {
              return const Text('Something went wrong');
            }
            if (snapshot.connectionState == ConnectionState.waiting) {
              return const Text("Loading");
            }
            return ListView(
                children: snapshot.data!.docs.map((DocumentSnapshot document) {
              Map<String, dynamic> data =
                  document.data()! as Map<String, dynamic>;
              return ListTile(
                title: Text(data['hotel_name']), // 👈 You can access here
                subTitle: Text(data['hotel_email']),
              );
            }).toList());
          },
        ),
      ),
    );
  }
    Login or Signup to reply.
Please signup or login to give your own answer.

Back To Top
Search