Gets or sets the action that occurs across this constraint on when a row is deleted.
[Visual Basic] Overridable Public Property UpdateRule As Rule [C#] public Rule UpdateRule {virtual get; virtual set;} [C++] public: __property virtual Rule get_UpdateRule(); public: __property virtual void set_UpdateRule(Rule); [JScript] public function get UpdateRule() : Rule; public function set UpdateRule(Rule);
One of the Rule values. The default is Cascade.
The following example creates a ForeignKeyConstraint, sets various of its properties, and adds it to a DataTable object's ConstraintsCollection.
[Visual Basic]
' The next line goes into the Declarations section of the module: ' SuppliersProducts is a class derived from DataSet. Private myDataSet As SuppliersProducts Private Sub CreateConstraint() ' Declare parent column and child column variables. Dim pCol As DataColumn Dim cCol As DataColumn Dim myFKC As ForeignKeyConstraint ' Set parent and child column variables. pCol = MyDataSet.Tables("Suppliers).Columns("SupplierID") cCol = MyDataSet.Tables("Products").Columns("SupplieriD") myFKC = New ForeignKeyConstraint("SuppierFKConstraint", pCol, cCol) ' Set null values when a value is deleted. myFKC.DeleteRule = Rule.SetNull myFKC.UpdateRule = Rule.Cascade myFKC.AcceptRejectRule = AcceptRejectRule.Cascade ' Add the constraint, and set EnforceConstraints to true. myDataSet.Tables("Suppliers").Constraints.Add myFKC myDataSet.EnforceConstraints = True End Sub
ForeignKeyConstraint Class | ForeignKeyConstraint Members | System.Data Namespace | AcceptRejectRule | Rule