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HELP: User Log In From Connected in Access Database

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Join Date: Jul 2007

Posts: 12

Reputation: boss16thugz is an unknown quantity at this point

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boss16thugz boss16thugz is offline

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HELP: User Log In From Connected in Access Database

Jul 17th, 2007

Hi I am currently new in C#, I have finished exercising and studying how to code for console application. Then I plan to do a simple application. I started with a user log in. Where in the form will validate the username and password inputted by the user in an access database and if successful it will show MAIN screen.

Below is my simple code, please help me. I am really stuck with this one once I new how to manipulate the records it will be easier for me. I don't know what to code in my cmdLogin. I cannot access there the datareader. Please help me I really want to learn.

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
using System.Data.OleDb;

namespace Perfume_Biz
{
public partial class Login : Form
{

public Login()
{
InitializeComponent();
string strconn = "Provider=Microsoft.Jet.OLEDB.4.0; Data source=C:\\Perfume.mdb";
string strcmd = "select User_Name,Password from Users";
OleDbConnection OleConn = new OleDbConnection(strconn);
OleDbCommand OleCmd = new OleDbCommand(strcmd, OleConn);
OleConn.Open();
OleDbDataReader OleRead = OleCmd.ExecuteReader();
}

private void cmdcancel_Click(object sender, EventArgs e)
{
Application.Exit();
}

private void cmdclear_Click(object sender, EventArgs e)
{
txtpassword.Text = "";
txtusername.Text = "";
}

private void Login_Load(object sender, EventArgs e)
{

}

private void cmdlogin_Click(object sender, EventArgs e)
{

}

}
}

•

Join Date: Jun 2007

Posts: 322

Reputation: Hamrick will become famous soon enough

Solved Threads: 33

Hamrick

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Posting Whiz

Re: HELP: User Log In From Connected in Access Database

Jul 17th, 2007

If you want to use variables in more than one method, you should make them member variables instead of local variables.

The truth does not change according to our ability to stomach it.

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Join Date: Mar 2007

Posts: 53

Reputation: FoX_ is an unknown quantity at this point

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FoX_

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Junior Poster in Training

Re: HELP: User Log In From Connected in Access Database

Jul 17th, 2007

Try to read the table row by row and compare user name and password for each read.Please look at the code sample below...

 Help with Code Tags 
 C# Syntax (Toggle Plain Text) 
private void button1_Click(object sender, EventArgs e)
        {
 
            OleDbConnection con = new OleDbConnection(@"Provider=Microsoft.Jet.OLEDB.4.0; Data" +  "Source=myDB.mdb");
            OleDbCommand com = new OleDbCommand("SELECT User_Name,Password FROM Table1",con);
            OleDbDataReader reader;
            bool permit = false;
 
            try
            {
                con.Open();
                reader = com.ExecuteReader();
 
                while (reader.Read())
                {
                    if (InputName == (reader["User_Name"].ToString()) && InputPass == reader["Password"].ToString())
                    {
                        permit = true;
                        break;
                    }    
                }
                con.Close();
            }
 
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message);
            }
 
            if (permit == true)
                MessageBox.Show("Access granted");
            else
                MessageBox.Show("Acces denied");
private void button1_Click(object sender, EventArgs e)
        {
            
            OleDbConnection con = new OleDbConnection(@"Provider=Microsoft.Jet.OLEDB.4.0; Data" +  "Source=myDB.mdb");
            OleDbCommand com = new OleDbCommand("SELECT User_Name,Password FROM Table1",con);
            OleDbDataReader reader;
            bool permit = false;

            try
            {
                con.Open();
                reader = com.ExecuteReader();

                while (reader.Read())
                {
                    if (InputName == (reader["User_Name"].ToString()) && InputPass == reader["Password"].ToString())
                    {
                        permit = true;
                        break;
                    }    
                }
                con.Close();
            }

            catch (Exception ex)
            {
                MessageBox.Show(ex.Message);
            }

            if (permit == true)
                MessageBox.Show("Access granted");
            else
                MessageBox.Show("Acces denied");

You can also use a query which retrieves the user with the password in a try catch block.If no user found , catch the exception and tell it user.Here is a sample code below:

 Help with Code Tags 
 C# Syntax (Toggle Plain Text) 
OleDbDataReader read;
 
                try
                {
                    cmd = new OleDbCommand("SELECT User_Name FROM Table1 WHERE Password =" + Convert.ToInt32(textBox1.Text),con);
 
                    if(con.State == ConnectionState.Closed)
                        con.Open();
 
                    read = cmd.ExecuteReader();
                    read.Read();//You should read only once because you can //retrieve only one record(i.e, User_Name is unique)
 
                    textBox2.Text = read["User_Name"].ToString();
 
 
                    read.Close();
                    con.Close();
 
 
                }
 
                catch (Exception ex)
                {
                    MessageBox.Show(ex.Message);
                }
OleDbDataReader read;
                
                try
                {
                    cmd = new OleDbCommand("SELECT User_Name FROM Table1 WHERE Password =" + Convert.ToInt32(textBox1.Text),con);

                    if(con.State == ConnectionState.Closed)
                        con.Open();

                    read = cmd.ExecuteReader();
                    read.Read();//You should read only once because you can //retrieve only one record(i.e, User_Name is unique)

                    textBox2.Text = read["User_Name"].ToString();
                   

                    read.Close();
                    con.Close();
                   

                }

                catch (Exception ex)
                {
                    MessageBox.Show(ex.Message);
                }