Re: Parameters

[analyzer]

Thanks for your answer.

using System;
using MySql.Data;
using MySql.Data.MySqlClient;

namespace Täglich_PW_root
{
/// <summary>
/// Zusammenfassung für Class1.
/// </summary>
class Class1
{
/// <summary>
/// Der Haupteinstiegspunkt für die Anwendung.
/// </summary>
void MySQL_taeglich()
{
string Message = null;
string MyConnectionString = "Database=dbwetter1; Data Source=analyzer; User ID=root; Password=root";

string zeit = DateTime.Now.ToString("hh");
string datum = DateTime.Now.ToString("yyyy-mmm");

MySqlConnection MyConnection = new MySqlConnection(MyConnectionString);

MySqlCommand MySelect1 = new MySqlCommand("SELECT MAX(AktWind) FROM tblwind WHERE MessDatumWind= ?datum_para", MyConnection);

MySelect1.Parameters.Add("?datum_para", datum);

MySqlDataReader MyReader = null;

if (zeit != null)
{

try
{
MyConnection.Open();
Message = "Fehler beim Öffnen der Verbindung";
MyReader = MySelect1.ExecuteReader();
Message = "Fehler beim Ausführen von mySelect1";
Console.WriteLine("Max Pegel");
Console.WriteLine(MyReader["AktPegel"].ToString());
}

catch
{
Message = "Fehler bei der Datenbankverbindung aufgetreten";
}

finally
{
if (MyReader != null)
MyReader.Close();
MyConnection.Close();
}
}
else
Console.WriteLine("Es ist nicht 0:xx Uhr");
Console.WriteLine(Message);
Console.ReadLine();

}
[STAThread]
static void Main(string[] args)
{
Class1 cl1 = new Class1();
cl1.MySQL_taeglich();
}
}
}
In this application, there are two problems. First problem: Is the parameter so correkt? Second problem: There ist a exception: There is already an open DataReader associated with this Connection which must be closed first.