How you will set the datarelation between two columns in ADO.Net?

ADO.NET provides DataRelation object to set relation between two columns.

It helps to enforce the following constraints,a unique constraint, which guarantees that a column in the table contains no duplicates and a foreign-key constraint,which can be used to maintain referential integrity.
A unique constraint is implemented either by simply setting the Unique property of a data column to true, or by adding an instance of the UniqueConstraint class to the DataRelation object's ParentKeyConstraint.
As part of the foreign-key constraint, you can specify referential integrity rules that are applied at three points,when a parent record is updated,when a parent record is deleted and when a change is accepted or rejected