Thread: Connecting to MySQl database

Hi,

Trying to use c# to connect to a mysql database that I have set up on a server somewhere, but I am currently getting the following error:

Error 11 The type 'System.Data.Common.DbConnection' is defined in an assembly that is not referenced. You must add a reference to assembly 'System.Data, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089'. C:\Documents and Settings\mb21\My Documents\Visual Studio 2008\Projects\Database3\Database3\Form1.cs 17 25 Database3

The code I am using is the following:

Code:

using System;
using System.Linq;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
using System.Data.SqlClient;
using MySql.Data;
using MySql.Data.MySqlClient;

namespace Database3
{
    public partial class Form1 : Form
    {
        MySqlConnection conn = null;
        MySqlDataReader dr;
        MySqlCommand cmd = null;

        public Form1()
        {
            InitializeComponent();
        }

       


        private void DisplayErrors(MySqlException errSQLException)
        {
            for (int i = 0; i < errSQLException.Errors.Count; i++)
            {
                MessageBox.Show("Index # " + i + "\n" + "Error:" +
                    errSQLException.Errors[i].ToString() + "\n");
            }
        }

        private void btnConnect_Click_1(object sender, EventArgs e)
        {
            string strSQL = "Select * from users";
           
            try
            {
                cmd = new MySqlCommand(strSQL, conn);
                dr = cmd.ExecuteReader(CommandBehavior.SequentialAccess);

                while (dr.Read())
                {

                    txtData.Text = dr.GetString(1);
                    
                }
            }
            catch (MySqlException ex)
            {
                DisplayErrors(ex);
            }
            finally
            {
                dr.Close();
                conn.Close();
            }
        }

        private void Form1_Load_1(object sender, EventArgs e)
        {
            string strConnection = "SERVER=server;" + "DATABASE=database;" + "UID=username;" + "PASSWORD=password;";
                            //"Data Source = .\\SQLEXPRESS;" +
                            //"Initial Catalog=SampleDatabase.mdf;";// +
                           //"Integrated Security=SSPI;" +
                          // "User ID=mb21;" +
                           //"Password=mscim2010;";
            
        
            txtData.Text = "blah";//This line does run
            try
            {
                conn = new MySqlConnection(strConnection);
                txtData.Text = txtData.Text + "anything";//This line does run
                conn.Open();
              
            }
            catch (MySqlException ex)
            {
                DisplayErrors(ex);
                conn.Close();
            }
        }      
    }
}

There are several errors, all like the one on the top, which correspond to the following lines:

Code:

MySqlConnection conn = null;
MySqlDataReader dr;
MySqlCommand cmd = null;

private void DisplayErrors(MySqlException errSQLException)

I installed mysql connector.net version 6.1.3 and I am using a Visual Studio 2008 for developing the code.

I am new to C#, so would be grateful for any help. It seems the problem is lies with the declaration of the variables (conn, dr, cmd and errSQLException) but I can't see what the problem is. Any and all help is appreciated.

Brownie

Also trying to connection to a local mssql server, but not having any luck with that. Just if anyone is wondering why this

//"Data Source = .\\SQLEXPRESS;" +
//"Initial Catalog=SampleDatabase.mdf;";// +
//"Integrated Security=SSPI;" +
// "User ID=mb21;" +
//"Password=mscim2010;";

is commented out.

The end result of the code will be deployed on the Windows Mobile platform (if that helps in any way)
Brownie

Hey stumon,

Thanks for replying. The errors I am getting are all like the following:

The type 'System.Data.XXXXXXXXXX' is defined in an assembly that is not referenced. You must add a reference to assembly 'System.Data.......'

I don't know why it is using System.Data when they all should be MySql.Data. I do have a reference added for the MySql.Data that was downloaded with Connector.net, but maybe adding one for MySql.Data.MySqlClient might just do the trick.

Thanks again.
Brownie

Code:

using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
using System.Data.SqlClient

Is there a System.Data or two in there or what?