DataRelation.ChildKeyConstraint Proprietà

public:
 virtual property System::Data::ForeignKeyConstraint ^ ChildKeyConstraint { System::Data::ForeignKeyConstraint ^ get(); };

public virtual System.Data.ForeignKeyConstraint? ChildKeyConstraint { get; }

public virtual System.Data.ForeignKeyConstraint ChildKeyConstraint { get; }

member this.ChildKeyConstraint : System.Data.ForeignKeyConstraint

Public Overridable ReadOnly Property ChildKeyConstraint As ForeignKeyConstraint

Valore della proprietà

Oggetto ForeignKeyConstraint.

Esempio

Nell'esempio seguente viene impostata la UpdateRuleregola , DeleteRulee AcceptReject per l'oggetto ForeignKeyConstraintDataRelationassociato a .

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 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

Commenti

Se non esiste alcun oggetto associato ForeignKeyConstraint per questa relazione, verrà creato automaticamente e puntato a ChildKeyConstraint, quando la relazione viene aggiunta alla raccolta di relazioni.

Si applica a

Vedi anche

• AcceptRejectRule
• ParentKeyConstraint
• Rule