The following examples show how to use NQ to select all
objects of the specified type from a database. Store Pilots function is used to fill in the database.
For languages with generics support (Java5-6; .NET2.0-3.0):
01private static void SelectAllPilots() 02
{ 03
IObjectContainer container = Database(); 04
if (container != null) 05
{ 06
try 07
{ 08
IList<Pilot> result = container.Query<Pilot>(delegate(Pilot pilot) 09
{ 10
// each Pilot is included in the result 11
return true; 12
}); 13
ListResult(result); 14
} 15
catch (Exception ex) 16
{ 17
System.Console.WriteLine("System Exception: " + ex.Message); 18
} 19
finally 20
{ 21
CloseDatabase(); 22
} 23
} 24
}
01Private Shared Sub SelectAllPilots() 02
Dim container As IObjectContainer = Database() 03
If Not container Is Nothing Then 04
Try 05
Dim result As IList(Of Pilot) = container.Query(Of Pilot)(AddressOf AllPilotsMatch) 06
ListResult(result) 07
Catch ex As Exception 08
System.Console.WriteLine("System Exception: " + ex.Message) 09
Finally 10
CloseDatabase() 11
End Try 12
End If 13
End Sub
1Private Shared Function AllPilotsMatch(ByVal p As Pilot) As Boolean 2
' each Pilot is included in the result 3
Return True 4
End Function
For languages without generics support (Java1.1-1.4; .NET1.0):
01private static void SelectAllPilotsNonGeneric() 02
{ 03
IObjectContainer container = Database(); 04
if (container != null) 05
{ 06
try 07
{ 08
IObjectSet result = container.Query(new NonGenericPredicate()); 09
ListResult(result); 10
} 11
catch (Exception ex) 12
{ 13
System.Console.WriteLine("System Exception: " + ex.Message); 14
} 15
finally 16
{ 17
CloseDatabase(); 18
} 19
} 20
}
01private class NonGenericPredicate : Predicate 02
{ 03
public bool Match(object obj) 04
{ 05
// each Pilot is included in the result 06
if (obj is Pilot) 07
{ 08
return true; 09
} 10
return false; 11
} 12
}
01Private Shared Sub SelectAllPilotsNonGeneric() 02
Dim container As IObjectContainer = Database() 03
If Not container Is Nothing Then 04
Try 05
Dim result As IObjectSet = container.Query(New NonGenericPredicate()) 06
ListResult(result) 07
Catch ex As Exception 08
System.Console.WriteLine("System Exception: " + ex.Message) 09
Finally 10
CloseDatabase() 11
End Try 12
End If 13
End Sub
01Private Class NonGenericPredicate 02
Inherits Predicate 03
Public Function Match(ByVal obj As Object) As Boolean 04
' each Pilot is included in the result 05
If TypeOf obj Is Pilot Then 06
Return True 07
End If 08
Return False 09
End Function 10
End Class