Flutter - 如何循环嵌套集合并转换为 DataTable 行？

Question

所以我有这个数据库结构：

我需要为用户的锻炼获取每个锻炼的所有集合，然后将其显示在 DataTable 中。

      StreamBuilder<QuerySnapshot>(
      stream: FirebaseFirestore.instance
          .collection("workouts")
          .doc(workoutId)
          .collection("exercises")
          .snapshots(),
      builder: (BuildContext context, AsyncSnapshot<QuerySnapshot> snapshot) {
        if (!snapshot.hasData) {
          return const Text("There are no exercises");
        }

        return DataTable(
          decoration: BoxDecoration(
            border: Border.all(
              width: 2,
              color: kBlack,
            ),
          ),
          dataRowHeight: SizeConfig.screenHeight * 0.05,
          dataTextStyle: const TextStyle(
              fontSize: kAppButtonTextFontSize, color: kAppTextColor),
          headingRowHeight: SizeConfig.screenHeight * 0.05,
          headingTextStyle: const TextStyle(fontSize: kAppButtonTextFontSize),
          //horizontalMargin,
          columnSpacing: 20,
          showCheckboxColumn: true,
          showBottomBorder: false,
          dividerThickness: 3,
          columns: const [
            DataColumn(
              label: Text(
                "Set#",
                style: TextStyle(
                  fontStyle: FontStyle.italic,
                  color: kBlack,
                ),
              ),
              numeric: true,
            ),
            DataColumn(
              label: Text(
                "Weight",
                style: TextStyle(
                  fontStyle: FontStyle.italic,
                  color: kBlack,
                ),
              ),
              numeric: true,
              //tooltip: "This is Last Name",
            ),
            DataColumn(
              label: Text(
                "Reps",
                style: TextStyle(
                  fontStyle: FontStyle.italic,
                  color: kBlack,
                ),
              ),
              numeric: true,
            ),
            DataColumn(
              label: Text(
                "ToFailure",
                style: TextStyle(
                  fontStyle: FontStyle.italic,
                  color: kBlack,
                ),
              ),
              numeric: true,
            ),
          ],
          rows: _getExercises(snapshot),// Here I want to get the rows
        );
      });


    _getExercises(AsyncSnapshot<QuerySnapshot> snapshot) {
  setState(() {

//How to structure the data here so as to get DataRows

    snapshot.data!.docs.forEach((doc) {
      //print(
     //   'DOCUMENT DATA =' + doc.data().toString(),
     // );
      completedExerciseSetRows.add(
        DataRow(cells: [
          DataCell(Text()),
          
          DataCell(Text()),
          
          DataCell(Text()),

        ]),
      );
    });
  });