Solved

C# App not working in Windows 2000

Posted on 2009-07-13
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Last Modified: 2013-12-17
I have an application written in C# using Microsoft Visual Studio 2005 Professional Edition Version 8.0.50727.762 (SP.050727-7600) AND Microsft .NET Framework Version 2.0.50727 SP1.

The app works on all the XP and Vista Machines but not on the 2000 Machines. Unfortunately upgrading the OS is not an option right now.
============
Microsoft Windows 2000
5.00.2195
Service Pack 4
============

When starting the application it prompts the user to scan there user id. On Return button click I get this error: (SEE Attached Text file "DEBUG.txt").

I can see that there is a problem where the app tries to access the database. (SEE Coded text below for my ODBC connection).

Are there any specific configurations that must be setup for the 2000 Machines?

Thanks any help here would be appreciated.
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
 
namespace ShippingTrackingSystem
{
    class clsMySqlODBCConnection
    {
        public int QueryType = 0;
        public System.Data.Odbc.OdbcConnection OdbcCon;
        public System.Data.Odbc.OdbcCommand OdbcCom;
        public System.Data.Odbc.OdbcDataReader OdbcDR;
        public string ConStr;
        //
        private string MySqlServer = "MydbServer";
        private string MySqlPort = "MydbPort";
        private string MySqlDatabase = "MydbName";
        private string MySqlUser = "MydbUser";
        private string MySqlUserPass = "MydbPass";
        private string MySqlOption = "MydbOption";
        //
        public clsMySqlODBCConnection()
        {
            ConStr = "DRIVER={MySQL ODBC 3.51 Driver};SERVER=" + MySqlServer + ";PORT=" + MySqlPort + ";DATABASE=" + MySqlDatabase + ";UID=" + MySqlUser + ";PWD=" + MySqlUserPass + ";OPTION=" + MySqlOption + "";
            OdbcCon = new System.Data.Odbc.OdbcConnection(ConStr);
 
            try
            {
                //txtLog.AppendText("Openning connection...\r\n");
                if (OdbcCon.State == ConnectionState.Closed)
                {
                    OdbcCon.Open();
                }
                //txtLog.AppendText("Connection opened\r\n");
                //MessageBox.Show("Connection opened\r\n");
            }
            catch (System.Data.Odbc.OdbcException Ex)
            {
                //txtLog.AppendText(Ex.Message + "\r\n");
                //MessageBox.Show("Could not access the database.\r\nPlease make sure you completed the fields with the correct information and try again.\r\n\r\nMore details:\r\n" + Ex.Message, "Database connection error", MessageBoxButtons.OK, MessageBoxIcon.Error);
            }
        }
        public void MySqlDisconnection()
        {
            if (OdbcCon.State == ConnectionState.Open)
            {
                OdbcCon.Close();
                //MessageBox.Show("Connected Closed\r\n");
            }
        }
        public void ShowTables()
        {
            if (OdbcCon.State == ConnectionState.Open)
            {
                OdbcCom = new System.Data.Odbc.OdbcCommand("SHOW TABLES", OdbcCon);
                OdbcDR = OdbcCom.ExecuteReader();
                //txtLog.AppendText("Tables inside " + txtDatabase.Text + ":\r\n");
                while (OdbcDR.Read())
                {
                    //txtLog.AppendText(">> " + OdbcDR[0] + "\r\n");
                }
            }
        }
        public string[] MySQLQuery(string qry, int fldidx)
        {
            List<string> list = new List<string>();
 
            string tStr = null;     // the following is not needed: = Convert.ToString(null);
            if (OdbcCon.State == ConnectionState.Open)
            {
                OdbcCom = new System.Data.Odbc.OdbcCommand(qry, OdbcCon);
                if (fldidx >= 0)
                {
                    OdbcDR = OdbcCom.ExecuteReader();
                    while (OdbcDR.Read())
                    {
                        tStr = Convert.ToString(OdbcDR[fldidx]);
                        list.Add(tStr);
                    }
                }
                else
                {
                    OdbcCom.ExecuteNonQuery();
                    QueryType = 1;
                }
            }
            return list.ToArray();
        }
 
        public IDataReader MySQLQuery(string qry)
        {
            if (OdbcCon.State == ConnectionState.Open)
            {
                OdbcCom = new System.Data.Odbc.OdbcCommand(qry, OdbcCon);
                OdbcDR = OdbcCom.ExecuteReader();
            }
            return OdbcDR;
        }
 
        public void MySQLNONQuery(string qry)
        {
            if (OdbcCon.State == ConnectionState.Open)
            {
                OdbcCom = new System.Data.Odbc.OdbcCommand(qry, OdbcCon);
                OdbcCom.ExecuteNonQuery();
                QueryType = 1;
            }
        }
 
        public object InitializeCnnObject()
        {
            // Create and initilize a recordset to represent the User Table
            clsMySqlODBCConnection OpenConnection = new clsMySqlODBCConnection();
            return OpenConnection;
        }
    }
}

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DEBUG.txt
0
Comment
Question by:SaltyDawg
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8 Comments
 
LVL 18

Assisted Solution

by:UnifiedIS
UnifiedIS earned 125 total points
ID: 24841119
Try updating MDAC (microsoft data access components)
0
 
LVL 70

Accepted Solution

by:
Qlemo earned 250 total points
ID: 24841375
MDAC version should not be the problem when using ODBC drivers. However, there is no other clue at the moment, and updating to MDAC 2.8 does not hurt.

You did not show the calling method
ShippingTrackingSystem.clsEbtronUser.ValidateUser(String user)
, but I reckon it is calling InitializeCnnObject(). The method seems to return a NULL pointer, probably because you are catching ODBC errors, but not executing any error fallback code in case of connection failure. If you would at least output the error message, it might help.
0
 
LVL 1

Author Comment

by:SaltyDawg
ID: 24841456

        private void cmdEnter_Click(object sender, EventArgs e)
        {
            clsShippingTrackingSystem TrackingSystem = new clsShippingTrackingSystem();
            clsEbtronUser EbtronUser = new clsEbtronUser();
 
            ScanUserID = txtScanUserId.Text;
            TrackingSystem.SetUserString(ScanUserID);
 
            UserString = TrackingSystem.GetUserString();
            UserAccess = EbtronUser.ValidateUser(UserString);
 
            if (!UserAccess)
            {
                lblUserValidated.Text = "User Not Validated";
            }
            else
            {
                frmUserID.ActiveForm.Close();
            }
        }
        public bool ValidateUser(string user)
        {
            clsMySqlODBCConnection OpenConnection = new clsMySqlODBCConnection();
            clsShippingTrackingSystem TrackingSystem = new clsShippingTrackingSystem();
            //
            string UserID = null;
            string PermissionLevel = null;
            string strQry = "Select User.Id, Program_Permissions.Permission_Level FROM User, Program_Permissions WHERE User.UserString = '" + user + "' AND Program_Permissions.Id = User.Id AND Program_Permissions.Program_Id = '" + Convert.ToString(TrackingSystem.GetProgramID()) + "' LIMIT 0, 1";
            //
            OpenConnection.MySQLQuery(strQry);
            while (OpenConnection.OdbcDR.Read())
            {
                UserID = Convert.ToString(OpenConnection.OdbcDR["Id"]);
                PermissionLevel = Convert.ToString(OpenConnection.OdbcDR["Permission_Level"]);
                TrackingSystem.SetUserID(UserID);
                TrackingSystem.SetUserPermission(PermissionLevel);
 
                OpenConnection.MySqlDisconnection();
                return true;
            }
            OpenConnection.MySqlDisconnection();
            return false;
        }

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LVL 28

Assisted Solution

by:strickdd
strickdd earned 125 total points
ID: 24842199
I'm willing to bet that one of these objects is NULL

TrackingSystem.GetProgramID()
OpenConnection.OdbcDR["Id"]
OpenConnection.OdbcDR["Permission_Level"]

I would recommend executing the SQL you *THINK* is being executed against the DB and making sure that there is a non-NULL value in "Id" and "Permission_Level". If either value is NULL, *THAT* is your problem. If neither is NULL, then the .GetProgramID() is probably returning a NULL.
0
 
LVL 1

Author Comment

by:SaltyDawg
ID: 24843390
I checked everything. All my variables have the correct data including my query string. It seems to fail at: OpenConnection.MySQLQuery(strQry);

Again everything seems to work fine on XP and Vista so that's why I summized it being an issue with 2000. I am not sure if it's an configuration problem in 2000 or with the ODBC configuration or a .NET problem in 2000. Currently .NET version 2.0.50727 is installed
0
 
LVL 1

Author Comment

by:SaltyDawg
ID: 24860036
I found the issue. It was the ODBC. Turns out I did need the MySQL Connector/ODBC updated drivers for Win2000/NT. These were installed and now everything works.

Thanks
0
 
LVL 1

Author Comment

by:SaltyDawg
ID: 24860072
in the statement:
if (OdbcCon.State == ConnectionState.Open)

OdbcCon.State  was closed therefore returning a NULL to OdbcDR.

Thanks for all your help
        public IDataReader MySQLQuery(string qry)
        {
            if (OdbcCon.State == ConnectionState.Open)
            {
                OdbcCom = new System.Data.Odbc.OdbcCommand(qry, OdbcCon);
                OdbcDR = OdbcCom.ExecuteReader();
            }
            return OdbcDR;
        }

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0
 
LVL 1

Author Closing Comment

by:SaltyDawg
ID: 31602893
Thanks. I split the points but since Qlemo was closer and his post actually led me to coming to the solution I gave him more.
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