I googled file locking issues. Sheesh, The horror stories of programs like Quickbooks corrupting data files. Files getting locked when nobody is using them (A windows 7 bug that supposedly was fixed) and endless information about what not to do, or what does not work. Very little about what does work.
My application is oriented toward research where data is added, but rarely deleted. Doing a cleanup or purge operation is rare, but would be done by a single user with a backup made of the original (I automate backups since people always forget to do it). So I just instruct the user to make sure they are the only one accessing that database when doing so. Users always follow directions, um.... What I am considering is if two people are adding to the same project file at the same time, make a local database that has the new information, then do a merge later into the main project file later. This is a real situation anyways as data may be collected offsite on something like an iPad or laptop then merged into the main database later. Isolated operation with no internet access. Would work similar to the rules of accounting. Make a transaction log then close the books at the end of the day. Seems to work for the past few hundred years for the bean counters. If person X needs person Y's new data, they just run the merge operation. Hmm, I can think of multiple problems with this technique, or the aggravation the users may encounter. Need to think about it some more, ------------ Scott Doctor scott at scottdoctor.com
