Sync two SqlExpress using NHibernate
- by Christian
Hello,
I am creating a simple project management system which uses NHibernate for object storage. The underlying database is SQL express (at least currently for development).
The client runs on either the desktop or laptop. I know I could use web-services and store the DB only on the desktop, but this would force the desktop to be available all the time.
I am currently thinking about duplicating the DB, having two instances with "different data". To clarify, we are not talking about a productive app here, its a prototype.
One way to achieve this very simple would be the following process:
Client: Check if desktop DB is available (through web service)
Client: If yes, use desktop storage, no problem here
Client: If not, use own DB as storage
Client: Poll desktop regulary, as soon as it comes on, sync
Client: Switch to desktop storage
...
Desktop: Do not attempt any DB operation before checking for required sync
Desktop: If sync needed, do it...
My question is now, how would you sync? Assume 4 or 5 types of objects, all have GUID as identifiers. Would you always manually "lazy load" all objects of a certain type and feed them to the DB. Would you always drop the whole desktop DB in case the client DB may be newer and out of sync?
Again, I want to stress out, I am not assuming any conflicts or stale data, I basically just want to "copy the whole DB from the client". Would you use NHibernate for this? Or would you separate the copy process?
When I think about it, my questions comes down to this:
Is there any function from NHibernate:
SyncDBs_SourceWins_(SourceDB, TargetDB)
Thanks for help,
Chris
