摘 要
随着互联网的出现和发展，人们的生活进入了信息时代。在经济迅速发展的中国，信息技术发挥中巨大的作用。
二维码技术经过了20多年的信息推广和应用，其在信息管理和信息交换领域中发挥了巨大的作用。二维码应具有成本低、纠正能力强，可靠性高，且具有极强的防伪能力，因此被广泛的应用于各类网络应用、证卡和物流管理系统中。
云数据库市场的迅速发展极大的影响着数据库技术的发展方向，同时国内外提供云服务的IT巨头正急剧上升。生活在云端已经是不争的事实。
因此将二维码技术与云数据库技术相结合起来是一种趋势。
本文主要对二维码中的QR码及其与SinaAppEngine平台提数据库供的云数据库进行了研究，包括QR码的编码、QR码图像的预处理、QR的译码以及SinaAppEngine的整体架构、数据模型和其扩展性。在此研究的基础上，提出了将二维码技术与云数据库技术相结合起来应用的系统即基于QR码技术的云考勤系统。
该系统主要包括了录入信息模块、扫描卡片模块、考勤分析模块和关于我们模块几个模块，最后部署了使用环境，对其进行了相应的功能测试和性能测试。测试结果表明整个系统的所有子模块，后台数据库和云数据库均能很好的协同工作，能够实现用户的需求。
关键词：二维码技术、云数据库、QR码、考勤系统
Abstract
Along with the emergence and development of the Internet, people's life has entered the information age. In the rapid economic development of China, the information technology play great role.
The two-dimensional code technology through information popularization and application for more than 20 years, and it played a great role in the field of information management. Two-dimensional code has the advantages of low cost, high reliability, strong correcting ability, and anti-counterfeiting ability strong, so it is widely used in all kinds of applications, network card and the logistics management system.
The rapid development of cloud database market greatly affects the development direction of database technology, at the same time at home and abroad to provide cloud services giant IT is raising sharply. Living in the cloud has been the fact.
Therefore, combining the two-dimensional code technology and database technology is a kind of trend.
This paper focuses on the two-dimensional code in the QR code and SinaAppEngine platform to database for cloud database was studied, including the code, the QR code image preprocessing of QR codes, QR decoding and SinaAppEngine architecture, data model and its extension. On the basis of this study, puts forward the system of two-dimensional bar code technology and cloud database technology combined application that is based on cloud attendance system QR code technology.
The system mainly includes several modules, and finally deployed using the environment, to the corresponding functional testing and performance testing .Test results show that all sub modules of the system, the background database and cloud database can be a very good work together, to achieve the needs of users.
Keywords：The two-dimensional code technology; Cloud database; OR code; Attendance system
目 录
摘 要............................................................................................................................ 1 Abstract........................................................................................................................ 2 第一章 绪论.................................................................................................................. 5
1.1 课题的研究背景.............................................................................................. 5 1.2 相关研究现状................................................................................................. 6
1.2.1二维码技术的研究现状....................................................................... 6 1.2.2 云数据库的研究现状.......................................................................... 7 1.3 论文内容研究................................................................................................. 7 第二章 二维条形码技术的研究................................................................................ 8
2.1 二维条码的特征............................................................................................. 8 2.2 QR码的介绍.................................................................................................... 9
2.2.1 QR主要特点......................................................................................... 9 2.2.2 QR码与PDF417码和DM（Data Martix）码的比较.................... 10 2.2.3 QR码的符号特性............................................................................. 11 2.3 QR码的编码程序设计.................................................................................. 12
2.3.1 QR码的编码....................................................................................... 12 2.4 QR码图像的预处理...................................................................................... 14
2.4.1 图像的灰度化.................................................................................... 14 2.4.2 图像的中值滤波................................................................................ 14 2.4.3 图像的二值化.................................................................................... 15 2.5 QR码的译码程序设计 .................................................................................. 16
2.5.1 QR码的译码....................................................................................... 16 2.6本章小结........................................................................................................ 17 第三章 云数据库的研究............................................................................................ 18
3.1 云数据库概述............................................................................................... 18
3.1.1 云数据库的特性................................................................................ 19 3.1.2 云数据库是云时代发展的必然选择................................................ 20 3.1.3 云数据库与传统数据库的比较........................................................ 20 3.1.4 云数据库的影响................................................................................ 20 3.2 云数据库领域的研究问题......................................................................... 21
3.2.1 云数据库采用的数据模型................................................................ 21 3.3 云数据库的体系架构................................................................................. 23
3.3.1 采用键/值数据模型的云数据库体系架构...................................... 23 3.3.2 采用关系数据模型的云数据库体系架构........................................ 24 3.4 云数据库的数据访问.................................................................................. 25 3.5 SinaAppEngine云数据库 ........................................................................... 26
3.5.1 SinaAppEngine的介绍..................................................................... 26 3.5.2 SinaAppEngine的整体架构............................................................. 26 3.5.3 SinaAppEngine 云数据库的扩展性................................................ 28 3.5.4 SinaAppEngine 云数据库的高可靠性............................................ 28 3.5.5 SinaAppEngine 云数据库的安全性................................................ 29
基于二维码技术的云考勤系统的研究和应用—初稿
