Okay.. Currently i already had this code for my registration form

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

namespace Thesis
{
    public partial class Registration : Form
    {
        Form formParent = null;
        public Registration(Form par)
        {
            formParent = par;
            InitializeComponent();
        }

        private void Registration_FormClosed(object sender, FormClosedEventArgs e)
        {
            formParent.Show();
        }

        private void button1_Click(object sender, EventArgs e)
        {
            string connection = @"Data Source=.\SQLEXPRESS;AttachDbFilename=C:\Users\Granodiorit\Documents\Visual Studio 2008\Projects\Thesis\Thesis\Database1.mdf;Integrated Security=True;User Instance=True";
            SqlConnection cn = new SqlConnection(connection);
            try
            {
                cn.Open();
            }
            catch (Exception)
            {
                MessageBox.Show("Did not connect");
            }

            string username = UserName.Text;
            string password = Password.Text;
            string nickname = Nick.Text;
            string birthday = Birthday.Text;
            string ymail = Ymail.Text;
            string gmail = Gmail.Text;
            string hotmail = Hotmail.Text;
            string yaddress = YAddress.Text;
            string gaddress = GAddress.Text;
            string hotaddress = HotAddress.Text;

            /* -------------------- */

            SqlCommand command = new SqlCommand("select username from [user] where username=@Username", cn);
            command.Parameters.AddWithValue("@UserName", username);

            object result = command.ExecuteScalar();
            if (result != null) // found
            {
                MessageBox.Show("Username already used");
                return;
            }

            /* -------------------- */

            string sqlquery;

            sqlquery = "INSERT INTO [User] (Username, Password, Nick, Birthday, Ymail, Yaddress, Gmail, Gaddress, Hotmail, Hotaddress) VALUES (@UserName, @Password, @Nick, @Birthday, @YMail, @YAddress, @GMail, @GAddress, @Hotmail, @HotAddress)";
            command = new SqlCommand(sqlquery, cn);
            command.Parameters.AddWithValue("@UserName", username);
            command.Parameters.AddWithValue("@Password", password);
            command.Parameters.AddWithValue("@Nick", nickname);
            command.Parameters.AddWithValue("@Birthday", birthday);
            command.Parameters.AddWithValue("@YMail", ymail);
            command.Parameters.AddWithValue("@YAddress", yaddress);
            command.Parameters.AddWithValue("@GMail", gmail);
            command.Parameters.AddWithValue("@GAddress", gaddress);
            command.Parameters.AddWithValue("@Hotmail", hotmail);
            command.Parameters.AddWithValue("@HotAddress", hotaddress);
            command.ExecuteNonQuery();
            this.Close();
            formParent.Show();
        }



        internal void show()
        {
            throw new NotImplementedException();
        }

        private void Registration_Load(object sender, EventArgs e)
        {
            string connection = @"Data Source=.\SQLEXPRESS;AttachDbFilename=C:\Users\Granodiorit\Documents\Visual Studio 2008\Projects\Thesis\Thesis\Database1.mdf;Integrated Security=True;User Instance=True";
            SqlConnection cn = new SqlConnection(connection);
            try
            {
                cn.Open();
            }
            catch (Exception)
            {
                MessageBox.Show("Did not connect");
            }
        }

    }
}

and here is my Login form code

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


namespace Thesis
{
    public partial class Login : Form
    {
        public Login()
        {
            InitializeComponent();
        }

        private void button2_Click(object sender, EventArgs e)
        {
            this.Hide();
            Registration Form2 = new Registration(this);
            Form2.Show();
        }

        private void button1_Click(object sender, EventArgs e)
        {
            string connection = @"Data Source=.\SQLEXPRESS;AttachDbFilename=C:\Users\Granodiorit\Documents\Visual Studio 2008\Projects\Thesis\Thesis\Database1.mdf;Integrated Security=True;User Instance=True";
            SqlConnection cn = new SqlConnection(connection);
            try
            {
                cn.Open();
            }
            catch (Exception)
            {
                MessageBox.Show("Did not connect");
            }

            SqlCommand cmd = new SqlCommand ("SELECT * FROM [User]",cn);
            cmd.Connection = cn;
            SqlDataReader reader = null;
            reader = cmd.ExecuteReader();
            while (reader.Read())
            {
                if(LoginUserName.Text == (reader["Username"].ToString()) && LoginPassword.Text == (reader["Password"].ToString()))
                {
                    MessageBox.Show("Login Succeed");
                }
            }
        }

    }
}

I dont know.. But somehow, the message box to let me know that the login form is succeed is not pop out.. anyone can help with my problem?

Try to use this line of code.
Just simply change your own variable then run.
May this line of code can help you.

private void btnLogin_Click(object sender, EventArgs e)
        {
            SqlConnection Connect = new SqlConnection();
            Connect.ConnectionString = @"Data Source=BURBANK\SQLEXPRESS;" + "Initial Catalog= ERPdb;" + "Persist Security Info=True;" + "User ID=antonette;" + "Password=ilovemis";
            Connect.Open();
            SqlCommand cmd = new SqlCommand("SELECT ISNULL(username, '') AS username, ISNULL(password, '') AS password FROM employee WHERE username='" + txtUserName.Text + "' and password='" + txtPassword.Text + "'", Connect);

            SqlDataReader dr = cmd.ExecuteReader();

            string userText = txtUserName.Text;
            string passText = txtPassword.Text;

            if (dr.Read())
            {
                frmMain main = new frmMain();
                this.Hide();
                main.Show();
            }
            else
                MessageBox.Show("Invalid UserName or Password.");

            {
                dr.Close();
                Connect.Close();
            }

Edited 3 Years Ago by mike_2000_17: Fixed formatting

This article has been dead for over six months. Start a new discussion instead.