为何这个语句不执行

 Connection con = null;
        try {
            con = DBPool.getConnection();// 方法已经取得链接
            String sql = "UPDATE DEPATERMENT SET "
                    + " DEPTENG_NAME = ?  WHERE DEPTSTR_ID = ? ";
            System.out.println(sql);
            PreparedStatement stmt = con.prepareStatement(sql);
            stmt.setString(CodeBook.NUMBER_1, "ff");
            stmt.setString(CodeBook.NUMBER_2, "1001");
            stmt.executeUpdate();
            con.close();
        } catch (Exception ex) {
            ex.printStackTrace();
            throw new SQLException();
        } finally {
            con.close();
        }