这段代码是什么意思？

Question

以下是.Net Sdk中提供的代码示例:

Private Sub ReadOrderData(ByVal connectionString As String)
    Dim queryString As String = _
        "SELECT OrderID, CustomerID FROM dbo.Orders;"

    Using connection As New SqlConnection(connectionString)
        Dim command As New SqlCommand(queryString, connection)
        connection.Open()

        Dim reader As SqlDataReader = command.ExecuteReader()

        ' Call Read before accessing data.
        While reader.Read()
            Console.WriteLine(String.Format("{0}, {1}", _
                reader(0), reader(1)))
        End While

        ' Call Close when done reading.
        reader.Close()
    End Using
End Sub

我的问题:这个读者(0)实际上是调用此属性reader.item(0)的快捷方式吗？

Answer 1

reader(0)指的是检索到的行中的第一个字段.但是,OrderID在这种情况下,您最好按名称引用字段.

看一下SqlDataReader.Item属性.

这是索引属性.你可以在这里找到一些细节.