"行/列不存在数据。"Oledb 异常

Question

connection.Open();
OleDbCommand command = new OleDbCommand("SELECT [Names] FROM Test", 
connection);
OleDbDataReader reader = command.ExecuteReader();
string result = reader.GetValue(0).ToString();
        MessageBox.Show(result);
        connection.Close();

谁能帮忙？我收到"行/列不存在数据"，引发此错误

Answer 1

您没有调用读取方法

    OleDbDataReader reader = command.ExecuteReader();
    if(reader.Read())
    {
       string result = reader.GetValue(0).ToString();
       MessageBox.Show(result);
     }
    connection.Close();

这将只读取结果中的第一行。如果你想要所有的行，那么你将需要写一些这样的东西

    OleDbDataReader reader = command.ExecuteReader();        
    List<string> data = new List<string>();
    while(reader.Read())
    {
      data.Add(reader.GetValue(0).ToString());
    }        
    connection.Close();