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IsStored

ExtObjectContainer#isStored helps you to define if the object is stored in the database. The following example shows how to use it:

UtilityExample.cs: CheckStored
public static void CheckStored()
     {
      // create a linked list with length 10
      SensorPanel list = new SensorPanel().CreateList(10);
      File.Delete(Db4oFileName);
      IObjectContainer db = Db4oFactory.OpenFile(Db4oFileName);
      try 
       {
        // store all elements with one statement, since all elements are new    
        db.Store(list);
        Object sensor = (Object)list.Sensor;
        SensorPanel sp5 = list.Next.Next.Next.Next;
        System.Console.WriteLine("Root element "+list+" isStored: " 
+ db.Ext().IsStored(list));
        System.Console.WriteLine("Simple type  "+sensor+" isStored: " 
+ db.Ext().IsStored(sensor));
        System.Console.WriteLine("Descend element  "+sp5+" isStored: " 
+ db.Ext().IsStored(sp5));
        db.Delete(list);
        System.Console.WriteLine("Root element "+list+" isStored: " 
+ db.Ext().IsStored(list));
      } 
      finally 
       {
        db.Close();
      }
    }

UtilityExample.vb: CheckStored
Public Shared Sub CheckStored()
            ' create a linked list with length 10
            Dim list As SensorPanel = New SensorPanel().CreateList(10)
            File.Delete(Db4oFileName)
            Dim db As IObjectContainer = Db4oFactory.OpenFile(Db4oFileName)
            Try
                ' store all elements with one statement, 
                ' since all elements are new    
                db.Store(list)
                Dim sensor As Object = CType(list.Sensor, Object)
                Dim sp5 As SensorPanel = list.NextSensor.NextSensor. _ 
NextSensor.NextSensor
                System.Console.WriteLine("Root element " + list.ToString() _ 
+ " isStored: " + db.Ext().IsStored(list).ToString())
                System.Console.WriteLine("Simple type  " + sensor.ToString() _ 
+ " isStored: " + db.Ext().IsStored(sensor).ToString())
                System.Console.WriteLine("Descend element  " + sp5.ToString() _ 
+ " isStored: " + db.Ext().IsStored(sp5).ToString())
                db.Delete(list)
                System.Console.WriteLine("Root element " + list.ToString() _ 
+ " isStored: " + db.Ext().IsStored(list).ToString())
            Finally
                db.Close()
            End Try
        End Sub

Download example code:

VB.NET c#