数据表中的第一列值

Question

我有一个只有1个数据表和1行但有2列的数据集。 我想获得第一列的值。 我怎样才能得到它在vb.net

Answer 1

所有你需要的是

ds.Tables(0).Rows(0)(0) 

其中，ds是您的DataSet对象的名称。这将从第一个表的第一行返回第一列作为对象。

Answer 2

Private Sub PrintValues(ByVal myTable As DataTable) 
    Dim myRow As DataRow 
    Dim myColumn As DataColumn 
    For Each myRow in myTable.Rows 
     For Each myColumn In myTable.Columns 
      Console.WriteLine(myRow(myColumn)) 
      Exit For 
     Next 
    Next 
End Sub 

Answer 3

尝试用：

public class MainClass 
    Shared Sub Main() 
     Dim thisConnection As New SqlConnection("yourconnection") 
     Dim thisCommand As New SqlCommand _ 
     ("SELECT FirstField FROM YourTable",thisConnection) 
     Try 
     thisConnection.Open() 
     Dim thisReader As SqlDataReader = thisCommand.ExecuteReader() 
     While (thisReader.Read()) 
       MessageBox.Show(thisReader.GetValue(0)) 
     End While 
     Finally 
     thisConnection.Close() 
     End Try 
    End Sub 
End Class