Here I will explain how to create a login form with SQL Server. Before this I explained Creating Login Form with SQL Server in Window Form.

Step 1: login form

Drag and down two Labels (for username and password) and two text boxes and a Button (for submit) onto a Window Forms form and change their name to "usrtxt" and "passtxt".

username and password

Step 2: Database table

database table
Step 3: The code for the button click of the button is as in the following:

button click

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.SqlClient;

namespace First_Csharp_app

{

public partial class Form1 : Form

{

public Form1()

{

InitializeComponent();

}

private void button1_Click(object sender, EventArgs e)

{

try

{

if (!(usertxt.Text == string.Empty))

{

if (!(passtxt.Text == string.Empty))

{

String str = "server=MUNESH-PC;database=windowapp;UID=sa;password=123";

String query = "select * from data where username = '" + usertxt.Text + "'and password = '" + this.passtxt.Text + "'";

SqlConnection con = new SqlConnection(str);

SqlCommand cmd = new SqlCommand(query, con);

SqlDataReader dbr;

con.Open();

dbr = cmd.ExecuteReader();

int count = 0;

while (dbr.Read())

{

count = count + 1;

}

if (count == 1)

{

MessageBox.Show("username and password is correct");

}

else if (count > 1)

{

MessageBox.Show("Duplicate username and password", "login page");

}

else

{

MessageBox.Show(" username and password incorrect", "login page");

}

}

else

{

MessageBox.Show(" password empty", "login page");

}

}

else

{

MessageBox.Show(" username empty", "login page");

}

// con.Close();

}

catch (Exception es)

{

MessageBox.Show(es.Message);

}

}

}

}

Step 4: Run your application

If the username and/or password is not correct:

Run your application

If the username and password are correct:

username and password is correct