Hi Mauricio,
If the parent row is related to one or more child rows, deleting this
parent row will
violates the ForeignKeyConstraint, you need delete all the child rows
before
deleting the parent row.
Does this solve your problem?
If you still have problem on this issue, please be free to post on this
group,
Thanks!

Best regards,

Ying-Shen Yu [MSFT]
Microsoft Online Partner Support
Get Secure! - www.microsoft.com/security

This posting is provided "AS IS" with no warranties and confers no rights.
You should not reply this mail directly, "Online" should be removed before
sending, Thanks!

--------------------

microsoft.public.dotnet.framework.windowsforms:55388

Full Explanation - How trap exception coused by deleting row in
Constraint
This problem is often see with deleting by datagrid, and imposible trap
System.Data.InvalidConstraintException.

Here is problem solution satisfies in complete.
Code is in C#, but if you need just translate to vb.net, and it will
work too.

We catch this exception at application level, and if we detect that is
"System.Data.InvalidConstraintException" exception, just do nothing, or
just inform user that he can not delete this row.

Once you add this method, you can use it for different exception traps!

Best Regards
Milan Better

1.Step is to add event handler Application.ThreadException, in main
function of our project

[STAThread]
static void Main()
{
Application.ThreadException +=new
System.Threading.ThreadExceptionEventHandler(Application_ThreadException);
Application.Run(new MainForm());
}

private static void Application_ThreadException(object sender,
System.Threading.ThreadExceptionEventArgs e)
{
//Fill here
}

2.Step is fill event handler we just created!

private static void Application_ThreadException(object sender,
System.Threading.ThreadExceptionEventArgs e)
{
if(e.Exception is System.Data.InvalidConstraintException)
{
MessageBox.Show(e.Exception.Message,"Error - can not break business
rules",MessageBoxButtons.OK,MessageBoxIcon.Error);
return; //This code silent pass exception
}
else throw e.Exception; //all other exceptions which we do not handle
}