DataRelation.ParentKeyConstraint 屬性

定義

命名空間:

System.Data

組件:

System.Data.Common.dll

來源:

DataRelation.cs

取得 UniqueConstraint，確保 DataRelation 之父資料行中的值為唯一。

public:
 virtual property System::Data::UniqueConstraint ^ ParentKeyConstraint { System::Data::UniqueConstraint ^ get(); };

public virtual System.Data.UniqueConstraint? ParentKeyConstraint { get; }

member this.ParentKeyConstraint : System.Data.UniqueConstraint

Public Overridable ReadOnly Property ParentKeyConstraint As UniqueConstraint

屬性值

UniqueConstraint

UniqueConstraint，確保父資料行中的值是唯一的。

範例

下列範例會取得 ParentKeyConstraintDataRelation 物件的 。

Private Sub GetParentKeyConstraint()
    ' Get a DataRelation from a DataSet.
    Dim relation As DataRelation = _
        DataSet1.Relations("CustomerOrders")

    ' Get the relations parent key constraint.
    Dim constraint As UniqueConstraint = _
        relation.ParentKeyConstraint

    ' Get the constraint's DataColumns
    Dim constraintColumns() As DataColumn
    constraintColumns = constraint.Columns

    ' Print the column names.
    Dim i As Integer
    For i = 0 to constraintColumns.GetUpperBound(0)
       Console.WriteLine(constraintColumns(i).ColumnName.ToString())
    Next i
End Sub

另請參閱

• ChildKeyConstraint
• UniqueConstraint