AcceptRejectRule AcceptRejectRule AcceptRejectRule AcceptRejectRule Enum

Definizione

Determina l'azione eseguita quando viene chiamato il metodo AcceptChanges() o il metodo RejectChanges() su un oggetto DataTable con un vincolo ForeignKeyConstraint.Determines the action that occurs when the AcceptChanges() or RejectChanges() method is invoked on a DataTable with a ForeignKeyConstraint.

public enum class AcceptRejectRule
public enum AcceptRejectRule
type AcceptRejectRule = 
Public Enum AcceptRejectRule
Ereditarietà
AcceptRejectRuleAcceptRejectRuleAcceptRejectRuleAcceptRejectRule

Campi

Cascade Cascade Cascade Cascade 1

Le modifiche vengono estese alla relazione.Changes are cascaded across the relationship.

None None None None 0

Non viene eseguita alcuna azione (impostazione predefinita).No action occurs (default).

Esempi

L'esempio seguente crea una ForeignKeyConstraint, imposta diverse proprietà, tra cui la AcceptRejectRulee lo aggiunge a un DataTable dell'oggetto ConstraintCollection.The following example creates a ForeignKeyConstraint, sets various of its properties, including the AcceptRejectRule, and adds it to a DataTable object's ConstraintCollection.

private void CreateConstraint(DataSet dataSet, 
    string table1, string table2,string column1, string column2)
{
   // Declare parent column and child column variables.
   DataColumn parentColumn;
   DataColumn childColumn;
   ForeignKeyConstraint foreignKeyConstraint;

   // Set parent and child column variables.
   parentColumn = dataSet.Tables[table1].Columns[column1];
   childColumn = dataSet.Tables[table2].Columns[column2];
   foreignKeyConstraint = new ForeignKeyConstraint
      ("SupplierForeignKeyConstraint",  parentColumn, childColumn);

   // Set null values when a value is deleted.
   foreignKeyConstraint.DeleteRule = Rule.SetNull;
   foreignKeyConstraint.UpdateRule = Rule.Cascade;
   foreignKeyConstraint.AcceptRejectRule = AcceptRejectRule.None;

   // Add the constraint, and set EnforceConstraints to true.
   dataSet.Tables[table1].Constraints.Add(foreignKeyConstraint);
   dataSet.EnforceConstraints = true;
}
Private Sub CreateConstraint(dataSet As DataSet, _
   table1 As String, table2 As String, _
   column1 As String, column2 As String)

   ' Declare parent column and child column variables.
   Dim parentColumn As DataColumn
   Dim childColumn As DataColumn
   Dim foreignKeyConstraint As ForeignKeyConstraint

   ' Set parent and child column variables.
   parentColumn = dataSet.Tables(table1).Columns(column1)
   childColumn = dataSet.Tables(table2).Columns(column2)
   foreignKeyConstraint = New ForeignKeyConstraint _
      ("SupplierForeignKeyConstraint", parentColumn, childColumn)

   ' Set null values when a value is deleted.
   foreignKeyConstraint.DeleteRule = Rule.SetNull
   foreignKeyConstraint.UpdateRule = Rule.Cascade
   foreignKeyConstraint.AcceptRejectRule = AcceptRejectRule.None

   ' Add the constraint, and set EnforceConstraints to true.
   dataSet.Tables(table1).Constraints.Add(foreignKeyConstraint)
   dataSet.EnforceConstraints = True
End Sub

Commenti

Passa a un DataTable non sono finali fino a quando non si chiama il AcceptChanges (metodo).Changes to a DataTable are not final until you call the AcceptChanges method. Quando sia AcceptChanges oppure RejectChanges viene chiamato su una riga nella tabella padre, il AcceptRejectRule valore determina se le modifiche vengono propagate alle righe corrispondenti nella tabella figlio.When either AcceptChanges or RejectChanges is called on a row in the parent table, the AcceptRejectRule value determines whether or not changes are propagated to corresponding rows in the child table.

Si applica a

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