Trying to populate an ObservableCollection from a database using the Entity Framework. Everything was fine until I started working with linked tables.
I created the DeviceCategory and DeviceComplexity model, and now in the WyeModel I try to integrate them into the DeviceCategoryViewModel. Further, in DeviceCategoryViewModel, I indicated a request for taking information from the database, but I ran into a problem. How to fill in ObservableCollection with this information? I tried different ways, but it didn’t lead to anything, I just got more confused.
DeviceCategoriesViewModel
class DeviceCategoryViewModel
{
TechDContext dc = new TechDContext();
public int Device_category_id { get; set; }
public string Device_category_name { get; set; }
public int Device_complexity_id { get; set; }
public string Device_complexity_name { get; set; }
public static DeviceCategoryViewModel DeviceCaterogyVM(DeviceCategory deviceCategory, DeviceComplexity deviceComplexity)
{
return new DeviceCategoryViewModel
{
Device_category_id = deviceCategory.Device_category_id,
Device_category_name = deviceCategory.Category_name,
Device_complexity_id = deviceCategory.Device_complexity_id,
Device_complexity_name = deviceComplexity.Device_complexity_name
};
}
public void FillDeviceDategories()
{
var q = from cat in dc.DeviceCategories
join com in dc.DeviceComplexities on cat.Device_complexity_id equals com.Device_complexity_id
select new
{
Device_category_id = cat.Device_category_id,
Category_name = cat.Category_name,
Device_complexity_id = com.Device_complexity_id,
Device_complexity_name = com.Device_complexity_name
};
items = q;
deviceCategories = Convert(items);
}
public ObservableCollection<DeviceCategoryViewModel>
Convert(IEnumerable<object> original)
{
return new ObservableCollection<DeviceCategoryViewModel>(original.Cast<DeviceCategoryViewModel>());
}
private IEnumerable<object> items;
public IEnumerable<object> Items
{
get
{
return items;
}
}
private ObservableCollection<DeviceCategoryViewModel> deviceCategories;
public ObservableCollection<DeviceCategoryViewModel> DeviceCategories
{
get
{
FillDeviceDategories();
return deviceCategories;
}
}
DeviceCategory Model
[Table("device_categories")]
public class DeviceCategory
{
[Key]
[DatabaseGenerated(DatabaseGeneratedOption.Identity)]
public int Device_category_id { get; set; }
public string Category_name { get; set; }
//[ForeignKey]
public int Device_complexity_id { get; set; }
public DeviceCategory()
{
}
public DeviceCategory(string name, int complexity_id)
{
Category_name = name;
Device_complexity_id = complexity_id;
}
}
DeviceCompexity Model
[Table("device_complexities")]
public class DeviceComplexity
{
[Key]
[DatabaseGenerated(DatabaseGeneratedOption.Identity)]
public int Device_complexity_id { get; set; }
public string Device_complexity_name { get; set; }
public DeviceComplexity()
{
}
public DeviceComplexity(string name)
{
Device_complexity_name = name;
}
}
I now get an error in the conversion method
You'd try to cast your LINQ query result to ObservableCollection<DeviceCategoryViewModel> in separate Convert function.
Why not to directly collect your LINQ query result to ObservableCollection<DeviceCategoryViewModel>
Just use like this
var q = from cat in dc.DeviceCategories
join com in dc.DeviceComplexities on cat.Device_complexity_id equals com.Device_complexity_id
select new DeviceCategoryViewModel // <= Note This Line
{
Device_category_id = cat.Device_category_id,
Category_name = cat.Category_name,
Device_complexity_id = com.Device_complexity_id,
Device_complexity_name = com.Device_complexity_name
};
deviceCategories = new ObservableCollection<DeviceCategoryViewModel>(q);
OR if you want to get result after list then simply use q.ToList()
deviceCategories = new ObservableCollection<DeviceCategoryViewModel>(q.ToList());
I am using the Caliburn.Micro MVVM pattern.
I am writing an application that has 2 DataGrids, one holds a BindableCollection of RepairOrder, the other a BindableCollection WriteOff.
BindableCollection_WriteOff is property of BindableCollection_RepairOrder. (See the below code).
I need to find a way to write all the RepairOrder including the WriteOff associated with each RO. Besides RepairOrder class holding the WriteOff class, the WriteOff class does not have a way to tie the WriteOff to a RepairOrder.
Repair Order Class:
public class RepairOrder
{
public string Schedule { get; set; }
public string ControlNumber { get; set; }
public int Age { get; set; }
public double Value { get; set; }
public string Note { get; set; }
public double OrgValue { get; set; }
private List<WriteOff> _myWriteOffs;
public List<WriteOff> GetMyWriteOffs()
{
return _myWriteOffs;
}
public void AddMyWriteOff(WriteOff value)
{ _myWriteOffs.Add(value); }
public void DeleteMyWriteOff(WriteOff value)
{ _myWriteOffs.Remove(value); }
public RepairOrder(string CN, string SC, double VL)
{
ControlNumber = CN;
Schedule = SC;
Value = Math.Round(VL, 2);
Note = null;
_myWriteOffs = new List<WriteOff>();
}
public RepairOrder()
{
_myWriteOffs = new List<WriteOff>();
}
public static RepairOrder FromCSV(string CSVLine, string Sched)
{
string[] values = CSVLine.Split(',');
RepairOrder rep = new RepairOrder();
rep.ControlNumber = values[2];
rep.Value = Math.Round(double.Parse(values[5]),2);
rep.Age = int.Parse(values[4]);
rep.Schedule = Sched;
return rep;
}
}
Write Off Class:
public class WriteOff
{
private string _store;
public string Account { get; set; }
public string Description { get; set; }
public double WriteOffAmount { get; set; }
public string Schedule { get; set; }
public string Store
{
get {
if (String.IsNullOrEmpty(_store)) return "";
string temp = _store.Substring(0, 3);
return temp;
}
set { _store = value; }
}
public string Note { get; set; }
public WriteOff(string Acct, string Desc, double Amount, string _store)
{
Account = Acct;
Description = Desc;
WriteOffAmount = Amount;
Store = _store;
}
public string GetWOAccount() {
string SchedAccountNumber = "";
//{ "Navistar", "Cummins", "Misc", "Kenworth", "Mack/Volvo" }
switch (Account)
{
case "Navistar":
SchedAccountNumber = "222000";
break;
case "Cummins":
SchedAccountNumber = "223000";
break;
case "Misc":
SchedAccountNumber = "224500";
break;
default:
SchedAccountNumber = "";
break;
}
return SchedAccountNumber;
}
}
This question already has answers here:
SQLite .NET performance, how to speed up things?
(2 answers)
Closed 7 years ago.
I am having a hard time trying to save the data faster, to a local DB.
Even though this is a one time saving, when the app runs for the first time, it takes like 90 seconds, in a Lumia 920, to save "only" the "map tables".
What I do:
1) I call an API, where I receive all the grids, with its Xs, Ys, Map Id, etc.
2) I deserialize the info based on a class I have defined.
3) For each item, in that info, I save the "misc" info (since I will use it)
4) I save, in a GRIDS table, each grid inside the previous item.
This code snipet is what I use to deserialize the info, and call the function to save in the DB
public class Maps
{
public string id { get; set; }
public string name { get; set; }
public string height { get; set; }
public string width { get; set; }
public string tile { get; set; }
public string shopping_id { get; set; }
public string url { get; set; }
public string updated_at { get; set; }
public string created_at { get; set; }
public GridFirst gridFirst { get; set; }
public GridLast gridLast { get; set; }
public List<Grid> grid { get; set; }
public class GridFirst
{
public string id { get; set; }
public string x { get; set; }
public string y { get; set; }
public string maps_id { get; set; }
public string value { get; set; }
}
public class GridLast
{
public string id { get; set; }
public string x { get; set; }
public string y { get; set; }
public string maps_id { get; set; }
public string value { get; set; }
}
public class Grid
{
public string id { get; set; }
public string x { get; set; }
public string y { get; set; }
public string maps_id { get; set; }
public string value { get; set; }
}
public void deserializeAndConvert(string aaa)
{
JObject myGeneral = JObject.Parse(aaa);
IList<JToken> results = myGeneral["resp"].Children().ToList();
// serialize JSON results into .NET objects
IList<Maps> searchResults = new List<Maps>();
foreach (JToken result in results)
{
Maps searchResult = JsonConvert.DeserializeObject<Maps>(result.ToString());
searchResults.Add(searchResult);
}
var respuesta = from data in searchResults
select new
{
id = data.id,
name = data.name,
height = data.height,
width = data.width,
tile = data.tile,
url = data.url,
lastX = data.gridLast.x,
lastY = data.gridLast.y,
grid = data.grid
};
foreach (var a in respuesta)
{
Database_Controller.getReadyToSaveData("mapinfo", 8, a.id, a.name, a.height, a.width, a.tile, a.url, a.lastX, a.lastY, "", "", "", "", "", "", "");
foreach (var data in a.grid)
{
Database_Controller.getReadyToSaveData("mapgrid", 5, data.id, data.x, data.y, data.maps_id, data.value, "", "", "", "", "", "", "", "", "", "");
}
}
}
}
And these are the functions that save the data, in the DB
public static void getReadyToSaveData(string dbName, int numberOfParams, string param1, string param2, string param3, string param4, string param5, string param6, string param7, string param8, string param9, string param10, string param11, string param12, string param13, string param14, string param15)
{
List<string> myParams = new List<string>();
myParams.Add(param1);
myParams.Add(param2);
myParams.Add(param3);
myParams.Add(param4);
myParams.Add(param5);
myParams.Add(param6);
myParams.Add(param7);
myParams.Add(param8);
myParams.Add(param9);
myParams.Add(param10);
myParams.Add(param11);
myParams.Add(param12);
myParams.Add(param13);
myParams.Add(param14);
myParams.Add(param15);
List<string> myParamsToDB = new List<string>();
for (var i = 0; i < numberOfParams; i++)
{
myParamsToDB.Add(myParams[i]);
}
insertData(dbName, myParamsToDB);
}
public static void insertData(string dbName, List<string> paramsToGo)
{
try
{
using (var connection = new SQLiteConnection("Unicenter.sqlite"))
{
if (dbName == "mapgrid")
{
using (var statement = connection.Prepare(#"INSERT INTO mapgrid (ID,X,Y,MAPS_ID,VALUE)
VALUES(?, ?,?,?,?);"))
{
statement.Bind(1, paramsToGo[0]);
statement.Bind(2, paramsToGo[1]);
statement.Bind(3, paramsToGo[2]);
statement.Bind(4, paramsToGo[3]);
statement.Bind(5, paramsToGo[4]);
// Inserts data.
statement.Step();
statement.Reset();
statement.ClearBindings();
}
}
if (dbName == "mapinfo")
{
using (var statement = connection.Prepare(#"INSERT INTO mapinfo (ID,NAME,HEIGHT,WIDTH,TILE,URL,LASTX,LASTY)
VALUES(?, ?,?,?,?,?,?,?);"))
{
statement.Bind(1, paramsToGo[0]);
statement.Bind(2, paramsToGo[1]);
statement.Bind(3, paramsToGo[2]);
statement.Bind(4, paramsToGo[3]);
statement.Bind(5, paramsToGo[4]);
statement.Bind(6, paramsToGo[5]);
statement.Bind(7, paramsToGo[6]);
statement.Bind(8, paramsToGo[7]);
// Inserts data.
statement.Step();
statement.Reset();
statement.ClearBindings();
}
}
}
}
catch (Exception ex)
{
Debug.WriteLine("Exception\n" + ex.ToString());
}
}
***Edit: As a kind reminder, in case some people does not see the tags (and mark this question as duplicated), this is FOR WINDOWS PHONE 8.1, so, the functions, references and classes ARE different from plain c#
Any idea on how to make it faster? ... What am I doing wrong?
you can use parallel.for loop which is more faster if you have large data or you can easily check each loop how much time it takes to execute in VS-2015
I have this:
public class Blah
{
public int id { get; set; }
public string blahh { get; set; }
}
public class Doh
{
public int id { get; set; }
public string dohh { get; set; }
public string mahh { get; set; }
}
public List<???prpClass???> Whatever(string prpClass)
where string prpClass can be "Blah" or "Doh".
I would like the List type to be class Blah or Doh based on what the string prpClass holds.
How can I achieve this?
EDIT:
public List<prpClass??> Whatever(string prpClass)
{
using (var ctx = new ApplicationDbContext())
{
if (prpClass == "Blah")
{
string queryBlah = #"SELECT ... ";
var result = ctx.Database.SqlQuery<Blah>(queryBlah).ToList();
return result;
}
if (prpClass == "Doh")
{
string queryDoh = #"SELECT ... ";
var result = ctx.Database.SqlQuery<Doh>(queryDoh).ToList();
return result;
}
return null
}
}
you have to have a common supertype:
public interface IHaveAnId
{
int id { get;set; }
}
public class Blah : IHaveAnId
{
public int id { get; set; }
public string blahh { get; set; }
}
public class Doh : IHaveAnId
{
public int id {get;set;}
public string dohh { get; set; }
public string mahh { get; set; }
}
then you can do:
public List<IHaveAnId> TheList = new List<IHaveAnId>();
and in some method:
TheList.Add(new Blah{id=1,blahh = "someValue"});
TheList.Add(new Doh{id =2, dohh = "someValue", mahh = "someotherValue"});
to iterate through the list:
foreach(IHaveAnId item in TheList)
{
Console.WriteLine("TheList contains an item with id {0}", item.id);
//item.id is allowed since you access the property of the class over the interface
}
or to iterate through all Blahs:
foreach(Blah item in TheList.OfType<Blah>())
{
Console.WriteLine("TheList contains a Blah with id {0} and blahh ='{1}'", item.id, item.blahh);
}
Edit:
the 2 methods and a int field holding the autovalue:
private int autoValue = 0;
public void AddBlah(string blahh)
{
TheList.Add(new Blah{id = autovalue++, blahh = blahh});
}
public void AddDoh(string dohh, string mahh)
{
TheList.Add(new Doh{id = autovalue++, dohh = dohh, mahh = mahh});
}
Another Edit
public List<object> Whatever(string prpClass)
{
using (var ctx = new ApplicationDbContext())
{
if (prpClass == "Blah")
{
string queryBlah = #"SELECT ... ";
var result = ctx.Database.SqlQuery<Blah>(queryBlah).ToList();
return result.Cast<object>().ToList();
}
if (prpClass == "Doh")
{
string queryDoh = #"SELECT ... ";
var result = ctx.Database.SqlQuery<Doh>(queryDoh).ToList();
return result.Cast<object>.ToList();
}
return null;
}
}
in the view you then have to decide what type it is. In asp.net MVC you can use a display template and use reflection to get a good design. But then i still don't know what technology you are using.
Yet another Edit
TestClass:
public class SomeClass
{
public string Property { get; set; }
}
Repository:
public static class Repository
{
public static List<object> Whatever(string prpClass)
{
switch (prpClass)
{
case "SomeClass":
return new List<SomeClass>()
{
new SomeClass{Property = "somestring"},
new SomeClass{Property = "someOtherString"}
}.Cast<object>().ToList();
default:
return null;
}
}
}
And a controller action in mvc:
public JsonResult Test(string className)
{
return Json(Repository.Whatever("SomeClass"),JsonRequestBehavior.AllowGet);
}
then i called it with: http://localhost:56619/Home/Test?className=SomeClass
And got the result:
[{"Property":"somestring"},{"Property":"someOtherString"}]
Is this what you are trying to do?
public class Blah
{
public int id { get; set; }
public string blahh { get; set; }
}
public class Doh
{
public int id { get; set; }
public string dohh { get; set; }
public string mahh { get; set; }
}
class Program
{
public static List<T> Whatever<T>(int count) where T: new()
{
return Enumerable.Range(0, count).Select((i) => new T()).ToList();
}
static void Main(string[] args)
{
var list=Whatever<Doh>(100);
// list containts 100 of "Doh"
}
}
I need to show the number of hours in a Grid, how ever when I use a method to get all of the columns, the results show the Date.
This is my scenario.
(My Entities)
public class Turno
{
public int Cod_Turno { get; set; }
public string Des_Turno { get; set; }
public string Des_NombreCorto { get; set; }
public DateTime Hor_Inicio { get; set; }
public DateTime Hor_Fin { get; set; }
public bool Flag_Activo { get; set; }
}
This is my Access Layer
public IList<Turno> Listar()
{
var turnos = new List<Turno>();
var comando = _baseDatos.GetStoredProcCommand("HOR_Listar_Turno");
using (var lector = _baseDatos.ExecuteReader(comando))
{
while (lector.Read())
{
turnos.Add(new Turno
{
Cod_Turno = lector.GetInt32(lector.GetOrdinal("Cod_Turno")),
Des_Turno = lector.GetString(lector.GetOrdinal("Des_Turno")),
Des_NombreCorto = lector.GetString(lector.GetOrdinal("Des_NombreCorto")),
Hor_Inicio = new DateTime(lector.IsDBNull(lector.GetOrdinal("Hor_Inicio")) ? 0 : lector.GetOrdinal("Hor_Inicio")),
Hor_Fin = new DateTime(lector.IsDBNull(lector.GetOrdinal("Hor_Fin")) ? 0 : lector.GetOrdinal("Hor_Fin")),
Flag_Activo = lector.GetBoolean(lector.GetOrdinal("Flag_Activo"))
});
}
}
comando.Dispose();
return turnos;
}
Is there a way to get a Time in the Line to get HOR_Inicio and HOR_Fin; I only need the hours and minutes.
If you want the hours and minutes as a string you could use DateTime.Now.ToString("HH:mm");