Change RowState to Added for existing record
Posted on 2011-03-15
I'm trying to set up my Winforms VB app to deal with multiuser operations (SQL Server for the database). One scenario to deal with is when a record is deleted by one user while another user is changing it; when the second user tries to save the changes, there is no record to update. This gives a DBConcurrencyException. Fine. There are two possible routes the second user may want to go at this point: 1) give up on the record (allow it to be deleted), or 2) restore the record using the data user #2 has in memory.
Option 1 is simple; toss the record from memory and go. Option 2 is proving surprisingly difficult to implement, because VB "knows" that the record is modified, not added, and therefore there ought to be a record in the database to match. It seems to me that if I reset the RowState to Added instead of Modified, I'll be ready, but RowState is a ReadOnly property, and I can't find a way to change it.
About the only thing I can think of is to create a new record and copy all of the items from the old record to the new record, then delete the old record and save the new. But that's pretty tedious (particularly since I have 10 child tables that will need the same treatment). Is there a simpler way?
Any other thoughts on traps to beware of for multiuser ops are welcome.