For a school project we have to make a Windows Phone 7.1 application. It has to use a local database, and we have to use LINQ and Bing Maps for this.
We are making an application that will retrieve routes from a database. Each route has some waypoints.
Now, we made 3 tables (more actually, but only those 3 are relevant at the moment), namely “Route”, “Waypoint” and “RouteWaypointLink”. You can see their classes below
Route:
[Table]
public class Route : INotifyPropertyChanged, INotifyPropertyChanging
{
public event PropertyChangingEventHandler PropertyChanging;
public event PropertyChangedEventHandler PropertyChanged;
private int idRouteValue;
private string nameValue;
[Column(IsPrimaryKey = true, IsDbGenerated = true, AutoSync = AutoSync.OnInsert)]
public int IDRoute
{
get
{
return idRouteValue;
}
private set
{
NotifyPropertyChanging("IDRoute");
idRouteValue = value;
NotifyPropertyChanged("IDRoute");
}
}
[Column]
public string Name
{
get
{
return nameValue;
}
set
{
NotifyPropertyChanging("Name");
nameValue = value;
NotifyPropertyChanged("Name");
}
}
/// <summary>
///
/// </summary>
/// <param name="propertyName"></param>
private void NotifyPropertyChanging(string propertyName)
{
if (PropertyChanging != null)
{
PropertyChanging(this, new PropertyChangingEventArgs(propertyName));
}
}
/// <summary>
///
/// </summary>
/// <param name="propertyName"></param>
private void NotifyPropertyChanged(string propertyName)
{
if (PropertyChanged != null)
{
PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
}
}
public override string ToString()
{
return "[" + IDRoute + "] " + Name;
}
}
Waypoint:
[Table]
public class Waypoint : INotifyPropertyChanged, INotifyPropertyChanging
{
public event PropertyChangingEventHandler PropertyChanging;
public event PropertyChangedEventHandler PropertyChanged;
private int idWaypointValue;
private string nameValue;
private double gpsLongitudeValue;
private double gpsLatitudeValue;
private string descriptionValue;
[Column(IsPrimaryKey = true, IsDbGenerated = true, AutoSync = AutoSync.OnInsert)]
public int IDWaypoint
{
get
{
return idWaypointValue;
}
private set
{
NotifyPropertyChanging("IDWaypoint");
idWaypointValue = value;
NotifyPropertyChanged("IDWaypoint");
}
}
[Column]
public string Name
{
get
{
return nameValue;
}
set
{
NotifyPropertyChanging("Name");
nameValue = value;
NotifyPropertyChanged("Name");
}
}
[Column]
public double GPSLongitude
{
get
{
return gpsLongitudeValue;
}
set
{
NotifyPropertyChanging("GPSLongitude");
gpsLongitudeValue = value;
NotifyPropertyChanged("GPSLongitude");
}
}
[Column]
public double GPSLatitude
{
get
{
return gpsLatitudeValue;
}
set
{
NotifyPropertyChanging("GPSLatitude");
gpsLatitudeValue = value;
NotifyPropertyChanged("GPSLatitude");
}
}
[Column]
public string Description
{
get
{
return descriptionValue;
}
set
{
NotifyPropertyChanging("Description");
descriptionValue = value;
NotifyPropertyChanged("Description");
}
}
/// <summary>
///
/// </summary>
/// <param name="propertyName"></param>
private void NotifyPropertyChanging(string propertyName)
{
if (PropertyChanging != null)
{
PropertyChanging(this, new PropertyChangingEventArgs(propertyName));
}
}
/// <summary>
///
/// </summary>
/// <param name="propertyName"></param>
private void NotifyPropertyChanged(string propertyName)
{
if (PropertyChanged != null)
{
PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
}
}
/// <summary>
///
/// </summary>
/// <returns></returns>
public override string ToString()
{
return Name;
}
}
RouteWaypointLink:
[Table]
public class RouteWaypointLink : INotifyPropertyChanged, INotifyPropertyChanging
{
public event PropertyChangingEventHandler PropertyChanging;
public event PropertyChangedEventHandler PropertyChanged;
private int idRouteWaypointLinkValue;
private EntityRef<Route> routeValue;
private EntityRef<Waypoint> waypointValue;
private int waypointIndexValue;
[Column(IsPrimaryKey = true, IsDbGenerated = true, AutoSync = AutoSync.OnInsert)]
public int IDRouteWaypointLink
{
get
{
return idRouteWaypointLinkValue;
}
private set
{
NotifyPropertyChanging("IDRouteWaypointLink");
idRouteWaypointLinkValue = value;
NotifyPropertyChanged("IDRouteWaypointLink");
}
}
[Association(IsForeignKey = true, Storage = "routeValue")]
public Route Route
{
get
{
return routeValue.Entity;
}
set
{
NotifyPropertyChanging("Route");
routeValue.Entity = value;
NotifyPropertyChanged("Route");
}
}
[Association(IsForeignKey = true, Storage = "waypointValue")]
public Waypoint Waypoint
{
get
{
return waypointValue.Entity;
}
set
{
NotifyPropertyChanging("Waypoint");
waypointValue.Entity = value;
NotifyPropertyChanged("Waypoint");
}
}
[Column]
public int WaypointIndex
{
get
{
return waypointIndexValue;
}
set
{
NotifyPropertyChanging("Index");
waypointIndexValue = value;
NotifyPropertyChanged("Index");
}
}
/// <summary>
///
/// </summary>
/// <param name="propertyName"></param>
private void NotifyPropertyChanging(string propertyName)
{
if (PropertyChanging != null)
{
PropertyChanging(this, new PropertyChangingEventArgs(propertyName));
}
}
/// <summary>
///
/// </summary>
/// <param name="propertyName"></param>
private void NotifyPropertyChanged(string propertyName)
{
if (PropertyChanged != null)
{
PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
}
}
/// <summary>
///
/// </summary>
/// <returns></returns>
public override string ToString()
{
return waypointValue.Entity.ToString();
}
}
When we start our program, we want to fill it with some test data:
/// <summary>
///
/// </summary>
/// <param name="connection"></param>
public static void MakeDB(string connection)
{
RallyDatabase db = new RallyDatabase(connection);
//Temp
db.DeleteDatabase();
if (!db.DatabaseExists())
{
db.CreateDatabase();
#region waypoint
Waypoint w1 = new Waypoint();
w1.Name = "VVV Breda";
w1.GPSLatitude = 51.59380;
w1.GPSLongitude = 4.77963;
db.WaypointTable.InsertOnSubmit(w1);
Waypoint w2 = new Waypoint();
w2.Name = "Liefdeszuster";
w2.GPSLatitude = 51.59307;
w2.GPSLongitude = 4.77969;
db.WaypointTable.InsertOnSubmit(w2);
Waypoint w3 = new Waypoint();
w3.Name = "Valkenberg";
w3.GPSLatitude = 51.59250;
w3.GPSLongitude = 4.77969;
db.WaypointTable.InsertOnSubmit(w3);
#endregion
#region route
Route testRoute1 = new Route();
testRoute1.Name = "Kroegentocht";
db.RouteTable.InsertOnSubmit(testRoute1);
Route testRoute2 = new Route();
testRoute2.Name = "Bezienswaardighedentocht";
db.RouteTable.InsertOnSubmit(testRoute2);
#endregion
#region waypointlinks
RouteWaypointLink routeWaypointLink1 = new RouteWaypointLink();
routeWaypointLink1.Route = testRoute1;
routeWaypointLink1.Waypoint = w1;
routeWaypointLink1.WaypointIndex = 0;
db.RouteLinkTable.InsertOnSubmit(routeWaypointLink1);
RouteWaypointLink routeWaypointLink2 = new RouteWaypointLink();
routeWaypointLink2.Route = testRoute1;
routeWaypointLink2.Waypoint = w2;
routeWaypointLink2.WaypointIndex = 1;
db.RouteLinkTable.InsertOnSubmit(routeWaypointLink2);
//Wut, why does it work when this is commented?
RouteWaypointLink routeWaypointLink3 = new RouteWaypointLink();
routeWaypointLink3.Route = testRoute1;
routeWaypointLink3.Waypoint = w3;
routeWaypointLink3.WaypointIndex = 2;
db.RouteLinkTable.InsertOnSubmit(routeWaypointLink3);
RouteWaypointLink routeWaypointLink4 = new RouteWaypointLink();
routeWaypointLink4.Route = testRoute2;
routeWaypointLink4.Waypoint = w1;
routeWaypointLink4.WaypointIndex = 0;
db.RouteLinkTable.InsertOnSubmit(routeWaypointLink4);
RouteWaypointLink routeWaypointLink5 = new RouteWaypointLink();
routeWaypointLink5.Route = testRoute2;
routeWaypointLink5.Waypoint = w2;
routeWaypointLink5.WaypointIndex = 1;
db.RouteLinkTable.InsertOnSubmit(routeWaypointLink5);
#endregion
db.SubmitChanges();
}
}
However, when we try to run this, we get an error pointing to db.SubmitChanges():
SqlCeException was unhandled - A foreign key value cannot be inserted because a corresponding primary key value does not exist. [ Foreign key constraint name = FK_RouteWaypointLink_Route ]
Now the weird thing: When I comment the last 3 inserts of RouteWaypointLink it works fine, so then it looks like this:
#region waypointlinks
RouteWaypointLink routeWaypointLink1 = new RouteWaypointLink();
routeWaypointLink1.Route = testRoute1;
routeWaypointLink1.Waypoint = w1;
routeWaypointLink1.WaypointIndex = 0;
db.RouteLinkTable.InsertOnSubmit(routeWaypointLink1);
RouteWaypointLink routeWaypointLink2 = new RouteWaypointLink();
routeWaypointLink2.Route = testRoute1;
routeWaypointLink2.Waypoint = w2;
routeWaypointLink2.WaypointIndex = 1;
db.RouteLinkTable.InsertOnSubmit(routeWaypointLink2);
//Wut, why does it work when this is commented?
//RouteWaypointLink routeWaypointLink3 = new RouteWaypointLink();
//routeWaypointLink3.Route = testRoute1;
//routeWaypointLink3.Waypoint = w3;
//routeWaypointLink3.WaypointIndex = 2;
//db.RouteLinkTable.InsertOnSubmit(routeWaypointLink3);
//RouteWaypointLink routeWaypointLink4 = new RouteWaypointLink();
//routeWaypointLink4.Route = testRoute2;
//routeWaypointLink4.Waypoint = w1;
//routeWaypointLink4.WaypointIndex = 0;
//db.RouteLinkTable.InsertOnSubmit(routeWaypointLink4);
//RouteWaypointLink routeWaypointLink5 = new RouteWaypointLink();
//routeWaypointLink5.Route = testRoute2;
//routeWaypointLink5.Waypoint = w2;
//routeWaypointLink5.WaypointIndex = 1;
//db.RouteLinkTable.InsertOnSubmit(routeWaypointLink5);
#endregion
db.SubmitChanges();
Isn’t it weird that it does work when 2 RouteWaypointLinks are being inserted, but not when we try to create 5?
We also saw the problem further in the program (we’re pretty far actually, but this is holding us back), when we tried to add a few RouteWaypointLinks.
Does anyone have a clue of what’s going on? We appreciate any help!
Yours,
Tregan
Hmm it seems I have fixed it by adding a few things
Also, I changed the Associations to this:
It seems logical that I have to add columns that hold the primary keys from Route and Waypoint. But still, I don’t really understand why it would work when I added 2, but not when I added more.
Well it’s fixed now so all is good.