string connectString = "YourConnectionString";
                MsSql2008FeatureLayer markersLayer = new MsSql2008FeatureLayer(connectString, "YourTableName", "YourFeatureIDColumn");
                Collection<Feature> features = markersLayer.FeatureSource.GetAllFeatures(ReturningColumnsType.AllColumns);

                InMemoryMarkerOverlay markerOverlay = new InMemoryMarkerOverlay("MarkerOverlay");
                foreach (var feature in features)
                {
                    markerOverlay.FeatureSource.InternalFeatures.Add(feature);
                    //set your own popup information on each layer.
                }