DataSet.Relations 属性

定义

命名空间:

System.Data

程序集:

System.Data.Common.dll

Source:

DataSet.cs

获取用于将表链接起来并允许从父表浏览到子表的关系的集合。

public:
 property System::Data::DataRelationCollection ^ Relations { System::Data::DataRelationCollection ^ get(); };

public System.Data.DataRelationCollection Relations { get; }

member this.Relations : System.Data.DataRelationCollection

Public ReadOnly Property Relations As DataRelationCollection

属性值

DataRelationCollection

一个包含 DataRelationCollection 对象集合的 DataRelation。 如果 DataRelation 对象不存在，将返回空集合。

示例

以下示例通过 Relations 属性打印所有子表的列名。

Private Sub PrintChildRelationRows()
   ' Declare variable to hold the row values.
   Dim rowValues As String
   Dim dataSet As DataSet

   ' Get the DataSet of a DataGrid that is displaying data 
   ' of at least two tables.
   Dim table As DataTable = CType(DataGrid1.DataSource, DataTable)

   ' Navigate using the Relations.
   Dim relation As DataRelation
   Dim row As DataRow
   Dim column As DataColumn

   ' Print the names of each column in each table.
   For Each relation In dataSet.Relations
      For Each column in relation.ChildTable.Columns
          rowValues &= column.ColumnName & " "
      Next
    Next

    ' Display results.
    Console.WriteLine(rowValues)
   End Sub

另请参阅

• 在 ADO.NET 中使用数据集