Checkbox value only updating N in database

protected void Button7_Click(object sender, EventArgs e)
    {
        foreach (GridViewRow row in GridView1.Rows)
        {
            if (row.RowType == DataControlRowType.DataRow)
            {
                if (Session["Role_Name"] != null && !string.IsNullOrEmpty(Session["Role_Name"].ToString()))
                {
                    CheckBox chkAdd = (row.Cells[1].FindControl("CheckBox1") as CheckBox);
                    CheckBox chkEdit = (row.Cells[2].FindControl("CheckBox2") as CheckBox);
                    CheckBox chkView = (row.Cells[3].FindControl("CheckBox3") as CheckBox);
                    CheckBox chkDelete = (row.Cells[4].FindControl("CheckBox4") as CheckBox);
                    // string strID = row.Cells[0].Text;
                    string Pages = row.Cells[0].Text;
                    con.Open();
                    string query = "Update Role1 set [Add]='" + (chkAdd.Checked == true ? 'Y' : 'N') + "', [View]='" + (chkView.Checked == true ? 'y' : 'N') + "' ,[Edit]='" + (chkEdit.Checked == true ? 'y' : 'N') + "' ,[Delete]='" + (chkDelete.Checked == true ? 'y' : 'N') + "' where Pages ='" + Pages + "' and Role_Name='" + Session["Role_Name"].ToString() + "'";
                    SqlCommand cmd = new SqlCommand(query, con);
                    cmd.ExecuteNonQuery();
                    populateGridview();

                    con.Close();
                }
            }
        } 
    }