c# Login form with User Authentication with sql database : I am new to SQL and C#. I am working on a login form that checks if the user is an admin or a basic user. In my SQL I created a table that stores username, password, and role (admin or basic user). The saved data are the following: 
For admin: username = admin, password = admin, role = admin 
For basic user: username = user, password = user, role = user 
If the user enters username and password "admin" it should be directed to the admin page else it would be user page. This is my code.

    string query = "SELECT * from tbl_login WHERE Username = @username and password = @password";
                con.Open();
                SqlCommand sqlcmd = new SqlCommand(query, con);
                sqlcmd.Parameters.AddWithValue("@username", tbusername.Text);
                sqlcmd.Parameters.AddWithValue("@password", tbpswlog.Text);
                DataTable dtbl = new DataTable();
                SqlDataAdapter sqlsda = new SqlDataAdapter(sqlcmd);
                sqlsda.Fill(dtbl);
                
                con.Close();

                if (dtbl.Rows.Count == 1)
                {
                    this.Hide();
                    if (tbusername.Equals("admin"))
                    {
                        MessageBox.Show("You are logged in as an Admin");
                        AdminHome fr1 = new AdminHome();
                        fr1.Show();
                        this.Hide();
                    }
                    else
                    {
                        MessageBox.Show("You are logged in as a User");
                        UserHome fr2 = new UserHome();
                        fr2.Show();
                        this.Hide();
                    }

                   
                }
                else
                {
                    MessageBox.Show("Incorrect username or password");
                }
                
            }

I know this code lacks and wrong. Thank you 