DataRelation.ChildKeyConstraint Свойство

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

Значение свойства

ForeignKeyConstraint

Объект ForeignKeyConstraint.A ForeignKeyConstraint.

Примеры

В следующем примере задается UpdateRule DeleteRule правило, и AcceptReject для, ForeignKeyConstraint связанного с DataRelation .The following example sets the UpdateRule, DeleteRule, and AcceptReject rule for the ForeignKeyConstraint associated with the DataRelation.

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

Комментарии

Если для этой связи не существует ни одного связанного объекта ForeignKeyConstraint , оно будет создано автоматически и на которое указывает ChildKeyConstraint , когда отношение добавляется в коллекцию связей.If no associated ForeignKeyConstraint exists for this relationship, it will be created automatically, and pointed to by the ChildKeyConstraint, when the relation is added to the collection of relations.

Применяется к

См. также раздел

• AcceptRejectRule
• ParentKeyConstraint
• Rule