CSharp and SQL Server "LOG IN"

LOG IN

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 login

{

    public partial class formlogin : Form

    {

        public formlogin()

        {

            InitializeComponent();

        }

        private void btnLogin_Click(object sender, EventArgs e)

        {

            string constr = "data source=ACER-PC\\SQLEXPRESS;database = hr;integrated security = SSPI";

           

        string query="Select *from tblEmployees Where id='"+txtUsername.Text.Trim()+"'and name='"+textPassword.Text.Trim()+"'";

        SqlDataAdapter sda=new SqlDataAdapter(query,constr);

            DataTable dtbl=new DataTable();

            sda.Fill(dtbl);

            if(dtbl.Rows.Count ==1)

            {

                frmMain obj=new frmMain();

                this.Hide();

                obj.Show();

            }

            else{

                MessageBox.Show("error");

            }

        }

    }

}