TypeAlias constructor accepts 2 parameters:
Note that the runtimeType class should exist in your application when you configure the alias.
The alias matches are found by comparing full names of the stored and runtime classes
Let's declare a new TypeAlias
c#:
private static TypeAlias tAlias;
VB:
Private Shared tAlias As TypeAlias
The following method will initialize tAlias and configure db4o to use it:
01private static IConfiguration ConfigureClassAlias() 02
{ 03
// create a new alias 04
tAlias = new TypeAlias("Db4objects.Db4odoc.Aliases.Pilot, Db4objects.Db4odoc", "Db4objects.Db4odoc.Aliases.Driver, Db4objects.Db4odoc"); 05
// add the alias to the db4o configuration 06
IConfiguration configuration = Db4oFactory.NewConfiguration(); 07
configuration.AddAlias(tAlias); 08
// check how does the alias resolve 09
Console.WriteLine("Stored name for Db4objects.Db4odoc.Aliases.Driver: " + tAlias.ResolveRuntimeName("Db4objects.Db4odoc.Aliases.Driver, Db4objects.Db4odoc")); 10
Console.WriteLine("Runtime name for Db4objects.Db4odoc.Aliases.Pilot: " + tAlias.ResolveStoredName("Db4objects.Db4odoc.Aliases.Pilot, Db4objects.Db4odoc")); 11
return configuration; 12
}
01Private Shared Function ConfigureClassAlias() As IConfiguration 02
' create a new alias 03
tAlias = New TypeAlias("Db4objects.Db4odoc.Aliases.Pilot, Db4objects.Db4odoc", "Db4objects.Db4odoc.Aliases.Driver, Db4objects.Db4odoc") 04
' add the alias to the db4o configuration 05
Dim configuration As IConfiguration = Db4oFactory.NewConfiguration() 06
configuration.AddAlias(tAlias) 07
' check how does the alias resolve 08
Console.WriteLine("Stored name for Db4objects.Db4odoc.Aliases.Driver: " + tAlias.ResolveRuntimeName("Db4objects.Db4odoc.Aliases.Driver, Db4objects.Db4odoc")) 09
Console.WriteLine("Runtime name for Db4objects.Db4odoc.Aliases.Pilot: " + tAlias.ResolveStoredName("Db4objects.Db4odoc.Aliases.Pilot, Db4objects.Db4odoc")) 10
Return configuration 11
End Function
We can always check the results of adding an alias using resolveRuntimeName and resolveStoredName as you see in the example. Basically the same methods are used internally by db4o to resolve aliased names.
01private static void SaveDrivers(IConfiguration configuration) 02
{ 03
File.Delete(Db4oFileName); 04
IObjectContainer db = Db4oFactory.OpenFile(configuration, Db4oFileName); 05
try 06
{ 07
Driver driver = new Driver("David Barrichello", 99); 08
db.Set(driver); 09
driver = new Driver("Kimi Raikkonen", 100); 10
db.Set(driver); 11
} 12
finally 13
{ 14
db.Close(); 15
} 16
}
01Private Shared Sub SaveDrivers(ByVal configuration As IConfiguration) 02
File.Delete(Db4oFileName) 03
Dim db As IObjectContainer = Db4oFactory.OpenFile(configuration, Db4oFileName) 04
Try 05
Dim driver As Driver = New Driver("David Barrichello", 99) 06
db.Set(driver) 07
driver = New Driver("Kimi Raikkonen", 100) 08
db.Set(driver) 09
Finally 10
db.Close() 11
End Try 12
End Sub
Due to the alias configured the database will have Pilot classes saved. You can check it using ObjectManager or you can remove alias and read it from the database:
1private static void RemoveClassAlias(IConfiguration configuration) 2
{ 3
configuration.RemoveAlias(tAlias); 4
}
01private static void GetPilots(IConfiguration configuration) 02
{ 03
IObjectContainer db = Db4oFactory.OpenFile(configuration, Db4oFileName); 04
try 05
{ 06
IObjectSet result = db.Query(typeof(Pilot)); 07
ListResult(result); 08
} 09
finally 10
{ 11
db.Close(); 12
} 13
}
1Private Shared Sub RemoveClassAlias(ByRef configuration As IConfiguration) 2
configuration.RemoveAlias(tAlias) 3
End Sub
1Private Shared Sub GetPilots(ByVal configuration As IConfiguration) 2
Dim db As IObjectContainer = Db4oFactory.OpenFile(configuration, Db4oFileName) 3
Try 4
Dim result As IObjectSet = db.Get(GetType(Db4objects.Db4odoc.Aliases.Pilot)) 5
ListResult(result) 6
Finally 7
db.Close() 8
End Try 9
End Sub
Obvioulsly you can install the same alias again and read the stored objects using Driver class.