使用 flutter 中的时间戳或 firebase 服务器时间从 firestore 保存和查询数据

Question

Please I have a history page on my flutter app that I want to work on and I have been thinking of a way to store the data correctly in my firestore so that I can achieve the desired result as seen in the picture below

I would love to have data of thesame day stored in thesame container as seen in the picture above. My challenge is, I do not know how to structure my data to get the desired result.

here is what I have tried;

my Count class file is below although I am not sure if that's what I will really do.

class Count {
 String id;
 final int count;
 final createdOn;

 Count({this.id = '', required this.count, required this.createdOn});

 Map<String, dynamic> toJson() =>
     {'id': id, "count": count, "createdOn": createdOn};

 Count.fromSnapShot(DocumentSnapshot<Map<String, dynamic>> snapshot)
     : id = snapshot.id,
       count = snapshot.data()!["count"],
       createdOn = snapshot.data()!["createdOn"];
}

and this is where I send data to firestore using onpressed in button

 onPressed: () async {
                               exerciseCounter.increment();
                               final counter = exerciseCounter.count;

                               final FirebaseAuth auth = FirebaseAuth.instance;

                               final User? user = await auth.currentUser;

                               final uid = user?.uid;

                               final percents = FirebaseFirestore.instance
                                   .collection('exercise-percentage')
                                   .doc(uid)
                                   .collection("daily-percentage");

                               final percent = Count(
                                   count: counter,
                                   createdOn: FieldValue.serverTimestamp());

                               final json = percent.toJson();

                               await percents.add(json);
                             },

now I am not sure of the correct way to use streambuilder to get the data from firestore and join the data of thesame day in thesame container. I understand that I will need to use query method to query my data with the firestore serverTimeStamp but I don't know how to use it to fetch data of thesame day and display it as shown in the picture above.

I will appreciate it if someone can really help me out. It can just be with a simple example I can follow or by correcting and adding to my code. Thank you for your time.

Answer 1

I would love to have data of the same day stored in the same container as seen in the picture above.

You could have an extra field beside the createdOn one which holds the date in the following format YYYYMMDD.

This way, you can easily:

• Query the Firestore document for a specific day
• Use a set of count aggregation queries to calculate the KPIs/Counters for a specific day