Gets the ForeignKeyConstraint for the relation.
Assembly: System.Data (in System.Data.dll)
If no associated ForeignKeyConstraint exists for this relationship, it will be created automatically, and pointed to by the ChildKeyConstraint, when the relation is added to the collection of relations.
The following example sets the UpdateRule, DeleteRule, and AcceptReject rule for the ForeignKeyConstraint associated with the DataRelation.
Private Sub SetChildKeyConstraint(dataSet As DataSet) ' Set child and parent columns. Dim parentColumn As DataColumn = dataSet.Tables( _ "Suppliers").Columns("SupplierID") Dim childColumn As DataColumn = dataSet.Tables( _ "Products").Columns("SupplierID") Dim relation As DataRelation = New DataRelation( _ "SuppliersConstraint", parentColumn, childColumn) dataSet.Relations.Add(relation) Dim foreignKey As ForeignKeyConstraint = _ relation.ChildKeyConstraint foreignKey.DeleteRule = Rule.SetNull foreignKey.UpdateRule = Rule.Cascade foreignKey.AcceptRejectRule = AcceptRejectRule.Cascade End Sub