An unhandled exception of type 'System.Data.SqlClient.SqlExc

Question

 

 

using System;

using System.Collections.Generic;

using System.ComponentModel;

using System.Data;

using System.Drawing;

using System.Linq;

using System.Text;

using System.Threading.Tasks;

using System.Windows.Forms;

using System.Data.SqlClient;

namespace test

{

public partial class Form1 : Form

{

public Form1()

{

InitializeComponent();

}

private void button1_Click(object sender, EventArgs e)

{

SqlConnection cn = new SqlConnection("server = localhost; user id = root; password=admin1234; database = test");

cn.Open();

SqlCommand cmd = new SqlCommand("SELECT * FROM users where username = '" + txtusername.Text + "', and passw =' " + txtpassword.Text + "'", cn);

SqlDataReader dr;

dr = cmd.ExecuteReader();

int count = 0;

while (dr.Read())

{

count += 1;

}

if (count == 1)

{

MessageBox.Show("OK");

Form2 f2 = new Form2();

f2.Show();

}

else if (count > 0)

{

MessageBox.Show("Duplicate username and password");

}

{

MessageBox.Show("username or password note correct");

}

txtusername.Clear();

txtpassword.Clear();

}

}

}