ForeignKeyConstraint.AcceptRejectRule ForeignKeyConstraint.AcceptRejectRule ForeignKeyConstraint.AcceptRejectRule ForeignKeyConstraint.AcceptRejectRule Property

Definizione

Indica il tipo di operazione che dovrà essere eseguita in questo vincolo quando si chiama AcceptChanges().Indicates the action that should take place across this constraint when AcceptChanges() is invoked.

public:
 virtual property System::Data::AcceptRejectRule AcceptRejectRule { System::Data::AcceptRejectRule get(); void set(System::Data::AcceptRejectRule value); };
[System.Data.DataSysDescription("ForeignKeyConstraintAcceptRejectRuleDescr")]
public virtual System.Data.AcceptRejectRule AcceptRejectRule { get; set; }
member this.AcceptRejectRule : System.Data.AcceptRejectRule with get, set
Public Overridable Property AcceptRejectRule As AcceptRejectRule

Valore della proprietà

Uno dei valori di AcceptRejectRule.One of the AcceptRejectRule values. Tra i possibili valori sono compresi None e Cascade.Possible values include None, and Cascade. Il valore predefinito è None.The default is None.

Esempi

Nell'esempio seguente viene creato ForeignKeyConstraintun oggetto, AcceptRejectRulene viene impostato il valore e viene DataTable aggiunto il ConstraintCollectionvincolo a un oggetto.The following example creates a ForeignKeyConstraint, sets its AcceptRejectRule, and adds the constraint 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

Commenti

Le modifiche apportate a DataRow o DataTable non sono AcceptChanges finali fino a quando non viene richiamato il metodo.Changes to a DataRow or DataTable are not final until the AcceptChanges method is invoked. A questo punto, AcceptRejectRule determina il corso di azione su tutti i valori che sono stati modificati o eliminati.At that point, the AcceptRejectRule determines the course of action on any values that have been changed or deleted.

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