why is this exception error in my c# page

protected void Page_Load(object sender, EventArgs e)
    {
        SqlConnection con = new SqlConnection("Data Source=.;Integrated Security=true;Initial Catalog=myproject");
        SqlCommand cmd = new SqlCommand("Select * from room where roomstatus like occupied'",con);
        con.Open();
     
        GridView1.DataSource =cmd.ExecuteReader();
        GridView1.DataBind();
        con.Close();

    }