Method deleteUser

ch3/UserDao.java:17–41

(String id)

    final int FAIL = 0;

    public int deleteUser(String id) {
        int rowCnt = FAIL; //  insert, delete, update

        Connection conn = null;
        PreparedStatement pstmt = null;

        String sql = "delete from user_info where id= ? ";

        try {
            conn = ds.getConnection();
            pstmt = conn.prepareStatement(sql);
            pstmt.setString(1, id);
//        int rowCnt = pstmt.executeUpdate(); //  insert, delete, update
//        return rowCnt;
            return pstmt.executeUpdate(); //  insert, delete, update
        } catch (SQLException e) {
            e.printStackTrace();
            return FAIL;
        } finally {
            // close()를 호출하다가 예외가 발생할 수 있으므로, try-catch로 감싸야함.
//            try { if(pstmt!=null) pstmt.close(); } catch (SQLException e) { e.printStackTrace();}
//            try { if(conn!=null)  conn.close();  } catch (SQLException e) { e.printStackTrace();}
            close(pstmt, conn); //     private void close(AutoCloseable... acs) {
        }
    }

    public User selectUser(String id) throws Exception {
        User user = null;