Hi,
I need help to resolve this problem:
I would like to access a MDB file and query some data from it, under the debug mode, Locals window, I'm able to see the data inside the reader object if i query for the whole table using the syntax as shown below:
using (OleDbConnection AccessConnection = new OleDbConnection(@"Provider=Microsoft.Jet.OLEDB.4.0; User Id=; Password=; Data Source=C:\PVCTData\Measurement_Result.mdb"))
{
OleDbCommand cmd = new OleDbCommand("SELECT * FROM Results order by TestTimeDate", AccessConnection);
AccessConnection.Open();
OleDbDataReader reader;
reader = cmd.ExecuteReader();
MessageBox.Show(reader.GetValue(0).ToString());
reader.Close();
AccessConnection.Close();
return sn;
}
however, if i just want to retrieve one record by using the query "
SELECT top1 CellIDStr FROM Results order by TestTimeDate", the program will throw an exception:
exception {"No data exists for the row/column."}
System.Exception {System.InvalidOperationException}May i know what is the problem in my code? Thanks.