August 30th, 2004

Transactional Update using TableAdapters

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

Author

0 comments