As promised, I’ve put together a sample that demonstrates how to create a transactional update using the new Whidbey TableAdapters.
http://windowsforms.net/samples/ThreeLevelUpdate.zip
In this sample I create a Parent, Child and Grandchild relationship. The tables are named, Parent, Child and Grandchild… J
Using the sample you can see the differences between single table updates and a transactional update.
The single table update will commit each table individually and can get you in a partial state. If you delete a row in the Parent table, then delete a row in the child and grandchild table, then use the Simple Update, the update will fail. I did not implement cascading updates in the database. So, deleting a parent where children still exist is a relational no-no.
If you update the three tables with the “Smart Update” I use transaction and delete the rows before deleting the parents. Life is good.
Now I must fully acknowledge that this should be the out-of-the-box behavior. And for that I apologize. We did outline some ideas early on, but we ultimately didn’t get them done.
I promise to explain this further as I have time. I’ve been promising to get this out, so I wanted to at least get the sample up for others to take a look at.
Works in Everett
I should note that theirs nothing about this example that couldn’t be applied to Visual Studio 2003. I’m simply showing how to incorporate this work into our new TableAdapters.
Steve
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