public void CleanUpDatabase()
{
// Find:
// - conferences w/o participants
// - participants w/o streams
// - streams w/o bytes
ArrayList confs = new ArrayList(), parts = new ArrayList(), streams = new ArrayList();
#region Depth-first-search of tree
// By collecting a full list of the conferences, participants, and streams to be deleted
// we can more effeciently delete the objects by doing quick bulk deletes from the database,
// rather than transacting for each individual delete.
foreach (TreeNode yearNode in Nodes)
{
foreach (TreeNode monthNode in yearNode.Nodes)
{
foreach (TreeNode dateNode in monthNode.Nodes)
{
foreach (TreeNode confNode in dateNode.Nodes)
{
if (!confNode.Nodes.GetEnumerator().MoveNext()) // check for emptiness
{
confs.Add(confNode);
}
else
{
foreach (TreeNode partNode in confNode.Nodes)
{
if (!partNode.Nodes.GetEnumerator().MoveNext())
{
parts.Add(partNode);
}
else
{
foreach (TreeNode streamNode in partNode.Nodes)
{
if ((streamNode.Tag as Stream).Bytes <= 1)
{
streams.Add(streamNode);
}
}
}
}
}
}
}
}
}
#endregion
#region Transact on DB for Delete:
// - conferences
int[] confIDs = new int[confs.Count];
for (int cnt = 0; cnt < confIDs.Length; ++cnt)
{
confIDs[cnt] = ((confs[cnt] as TreeNode).Tag as Conference).ConferenceID;
}
DBHelper.DeleteConferences(confIDs);
// - participants
int[] partIDs = new int[parts.Count];
for (int cnt = 0; cnt < partIDs.Length; ++cnt)
{
partIDs[cnt] = ((parts[cnt] as TreeNode).Tag as Participant).ParticipantID;
}
DBHelper.DeleteParticipants(partIDs);
// - streams
int[] streamIDs = new int[streams.Count];
for (int cnt = 0; cnt < streamIDs.Length; ++cnt)
{
streamIDs[cnt] = ((streams[cnt] as TreeNode).Tag as Stream).StreamID;
}
DBHelper.DeleteStreams(streamIDs);
#endregion
// Delete from UI
RemoveNodes(confs);
RemoveNodes(parts);
RemoveNodes(streams);
// Find Conferences w/o end times
// (for simplicity, just get them from the DB again)
Conference[] allConfs = DBHelper.GetConferences();
foreach (Conference conf in allConfs)
{
if (conf.End == DateTime.MinValue)
{
DBHelper.CreateConferenceEndTime(conf.ConferenceID);
}
}
}