Updating Master – Detail Records

[Echooff3]

My application utilizes a dataset with a couple of One to Many relations. If the user adds a new record and adds information to the master part of the form and adds information to the detail part of the form then clicks save. The master record gets saved and the detail throws a “INSERT statement conflicted with the FOREIGN KEY constraint … The conflict occurred in “MasterTable”, “MasterTableID” .

My save routine goes like this:

Me.Validate () ‘ Validates the form
MasterBindingSource.EndEdit
MasterTableTableAdapter.Update(DataSet.MasterTable)
DetailBindingsource.EndEdit
DetailTableAdapter.Update(DataSet.DetailTable)
 

I checked the row data for the Master Table and it’s identity updated from 0 to the next ID. When I check the foreign column on the Detail table it’s still 0. So when the update hits the constraint is invalid and throws the error. Blaming the Master Table even though it has the updated ID. Is there something wrong in my EndEdit / Update Sequence that the foreign key on the detail table is not updating???

[Echooff3]

I think I have answered my issue. I removed the default FILL statement (in the form load event) that gets autogenerated in the IDE. My application pulls over 20K records so that would create a huge lag in performance. So when I called AddNew from the Master BindingSource it left the ID as 0. And sending 0 as the foreign key values to all the detail tables. So I created a query in my datatables to pull the Last record and load up the dataset intially. I don't understand why this works? Why is it necessary to fill the dataset before adding a new record?

When I update without calling inital Fill it updates the Master record fine but the changes don't propigate through the subtables. But if I call the fill first it does propigate???

Can some one explain this to me?