Return null value between two dates in sqflite and flutter - flutter

Question

i have spent three days for find solution but nothing , always have a same value NULL!
I create database and the function to calculate total in chossing period here :
1/ class Database
class DatabaseHelper {
static DatabaseHelper _databaseHelper; // Singleton DatabaseHelper
static Database _database; // Singleton Database
String clientTable = 'client_table';
String colId = 'id';
String colNumerotelephone = 'numerotelephone';
String colCode = 'code';
String colPrix = 'prix';
String colPriority = 'priority';
String colColor = 'color';
String colDate = 'date';
DatabaseHelper._createInstance(); // Named constructor to create instance of DatabaseHelper
factory DatabaseHelper() {
if (_databaseHelper == null) {
_databaseHelper = DatabaseHelper
._createInstance(); // This is executed only once, singleton object
}
return _databaseHelper;
}
Future<Database> get database async {
if (_database == null) {
_database = await initializeDatabase();
}
return _database;
}
Future<Database> initializeDatabase() async {
Directory directory = await getApplicationDocumentsDirectory();
String path = directory.path + 'clients.db';
var clientsDatabase =
await openDatabase(path, version: 1, onCreate: _createDb);
return clientsDatabase;
}
void _createDb(Database db, int newVersion) async {
await db.execute(
'CREATE TABLE $clientTable($colId INTEGER PRIMARY KEY AUTOINCREMENT, $colNumerotelephone TEXT,$colCode TEXT, '
'$colPrix REAL, $colPriority INTEGER, $colColor INTEGER,$colDate TEXT)');
}
.......
// code where i get the null value
Future claculTotalPeriod (String startDate, String endDate) async {
var totalClientperiod = await database;
var resulttotalperiod = await totalClientperiod.rawQuery("SELECT SUM($colPrix) AS TOTAL from $clientTable WHERE $colDate BETWEEN '$startDate' AND '$endDate'");
return resulttotalperiod.toList();
}
}
2/and this class for displaying database data
class ClientList extends StatefulWidget {
const ClientList({Key key}) : super(key: key);
#override
State<StatefulWidget> createState() {
return ClientListState();
}
}
class ClientListState extends State<ClientList> {
DatabaseHelper databaseHelper = DatabaseHelper();
List<Client> clientList;
double somme_period = 00;
String somme_total_period = "00.00";
String startDate='';
String endDate='';
TextEditingController startdate = TextEditingController();
TextEditingController finishdate = TextEditingController();
void calcul_total_period() async {
var totalSumPeriod = (await databaseHelper.claculTotalPeriod(startDate, endDate))[0]['TOTAL']; //['$startDate''$endDate'];
setState(() {
somme_period = totalSumPeriod ?? 00;
somme_total_period = somme.toStringAsFixed(2);
});
}
#override
Widget build(BuildContext context) {
if (clientList == null) {
clientList = [];
updateListView();
}
return Scaffold(
appBar: myAppBar(),
body: clientList.isEmpty
? Container(
color: Colors.white,
child: Center(
child: Padding(
padding: const EdgeInsets.all(16.0),
child: Text('ADD Client',
style: Theme.of(context).textTheme.bodyText2),
),
),
)
: Container(
color: Colors.white,
child: getClientsList(),
),
floatingActionButton: FloatingActionButton(
onPressed: () {
navigateToDetail(Client('', '', '', 3, 0, 0.0), 'new');
},
tooltip: 'Add',
shape: const CircleBorder(
side: BorderSide(color: Colors.black, width: 2.0)),
child: const Icon(Icons.add, color: Colors.black),
backgroundColor: Colors.white,
),
bottomNavigationBar: OutlinedButton(
onPressed: () {
showDialog(
context: context,
builder: (context) {
return Container(
margin: const EdgeInsets.all(20),
child: Card(
shape: RoundedRectangleBorder(
borderRadius: BorderRadius.circular(16),
),
color: Colors.white,
clipBehavior: Clip.antiAliasWithSaveLayer,
child: Column(
mainAxisSize: MainAxisSize.min,
children: <Widget>[
const SizedBox(height: 20,),
TextField(
controller: startdate,
//editing controller of this TextField
decoration: const InputDecoration(
icon: Icon(Icons.calendar_today), //icon of text field
labelText: "start date" //label text of field
),
readOnly: true,
//set it true, so that user will not able to edit text
onTap: () async {
DateTime pickedDate = await showDatePicker(
context: context,
initialDate: DateTime.now(),
firstDate: DateTime(2022,12),
lastDate: DateTime(2026,12));
if (pickedDate != null) {
print(
pickedDate); //pickedDate output format => 2021-03-10 00:00:00.000
String formattedDate =
DateFormat('yyyy-MM-dd').format(pickedDate);
print(
formattedDate); //formatted date output using intl package => 2021-03-16
setState(() {
startdate.text =
formattedDate;
startDate = startdate.text.toString(); //set output date to TextField value.
});
} else {}
},
),
const SizedBox(height: 20,),
TextField(
controller: finishdate,
//editing controller of this TextField
decoration: const InputDecoration(
icon: Icon(Icons.calendar_today), //icon of text field
labelText: "end date" //label text of field
),
readOnly: true,
//set it true, so that user will not able to edit text
onTap: () async {
DateTime pickedDate = await showDatePicker(
context: context,
initialDate: DateTime.now(),
firstDate: DateTime(2022,12),
lastDate: DateTime(2026,12));
if (pickedDate != null) {
print(
pickedDate); //pickedDate output format => 2021-03-10 00:00:00.000
String formattedDate =
DateFormat('yyyy-MM-dd').format(pickedDate);
print(
formattedDate); //formatted date output using intl package => 2021-03-16
setState(() {
finishdate.text =
formattedDate; //set output date to TextField value.
endDate = finishdate.text.toString();
});
} else {}
},
),
const SizedBox(height: 20,),
OutlinedButton(
onPressed: () {
calcul_total_period();
},
child: const Text(' period total')),
Padding(
padding: const EdgeInsets.all(8.0),
child: Text(
somme_total_period,
style: Theme.of(context).textTheme.headline5,
textAlign: TextAlign.center,
),
),
],
),
),
);
});
},
child: const Text('totalinperiod')),
);
}
void updateListView() {
final Future<Database> dbFuture = databaseHelper.initializeDatabase();
dbFuture.then((database) {
Future<List<Client>> clientListFuture = databaseHelper.getClientList();
clientListFuture.then((clientList) {
setState(() {
this.clientList = clientList;
count = clientList.length;
});
});
});
}
}
when i execute the code always i get the null value for the resulttotalperiod
can same one help me please.