ForeignKeyConstraint.UpdateRule Property

public:
 virtual property System::Data::Rule UpdateRule { System::Data::Rule get(); void set(System::Data::Rule value); };

public virtual System.Data.Rule UpdateRule { get; set; }

[System.Data.DataSysDescription("ForeignKeyConstraintUpdateRuleDescr")]
public virtual System.Data.Rule UpdateRule { get; set; }

member this.UpdateRule : System.Data.Rule with get, set

[<System.Data.DataSysDescription("ForeignKeyConstraintUpdateRuleDescr")>]
member this.UpdateRule : System.Data.Rule with get, set

Public Overridable Property UpdateRule As Rule

Property Value

One of the Rule values. The default is Cascade.

Attributes

DataSysDescriptionAttribute

Examples

The following example creates a ForeignKeyConstraint, sets various of its properties, and adds it to a DataTable object's ConstraintCollection.

' The next line goes into the Declarations section of the module:
' SuppliersProducts is a class derived from DataSet.
Private suppliersProducts As SuppliersProducts 

Private Sub CreateConstraint()
 ' Declare parent column and child column variables.
 Dim parentColumn As DataColumn
 Dim childColumn As DataColumn
 Dim fkConstraint As ForeignKeyConstraint

 ' Set parent and child column variables.
 parentColumn = suppliersProducts.Tables("Suppliers").Columns("SupplierID")
 childColumn = suppliersProducts.Tables("Products").Columns("SupplieriD")
 fkConstraint = New ForeignKeyConstraint( _
 "SuppierFKConstraint", parentColumn, childColumn)

 ' Set null values when a value is deleted.
 fkConstraint.DeleteRule = Rule.SetNull
 fkConstraint.UpdateRule = Rule.Cascade
 fkConstraint.AcceptRejectRule = AcceptRejectRule.Cascade

 ' Add the constraint, and set EnforceConstraints to true.
 suppliersProducts.Tables("Suppliers").Constraints.Add(fkConstraint)
 suppliersProducts.EnforceConstraints = True
End Sub

See also

• AcceptRejectRule
• Rule