Are the DataTable's inside a DataSet and did you add a relation between them
? Customer should be the parent and Orders the child.
Then you can add an expression column to the Orrders so it gets the name
from its parent Customer:
"Customer", typeof(string), "Parent(CustomerOrders).Name");
Then you can hide the foreign key column, see following link on how to hide
There is one problem, DataTable with expression columns may give error when
updating, so you need to remove them before update and re-add them after