2013-3-26

2013-3-26

毕业论文（设计）开题报告（文献综述）

 

第二篇：停车场管理系统毕业设计论文

停车场管理系统

摘 要

停车场停车场车辆管理系统是典型的信息管理系统,其开发的功能主要包括：通过计算机管理车辆和他人的联系信息，实现无纸化管理，通过查询分析，统计出各项数据，通过强大的查询和索检高效的索检出数据，提高办事效率。 经过分析,我们决定使用 MICROSOFT公司的 ACCESS作为后台数据库,设计出停车场车辆管理库， 使用 MICROSOFT公司的 VISUAL BASIC开发工具，利用其提供的各种面向对象的开发工具,尤其是ADO控件这一能方便而简洁操纵数据库的智能化对象,连接数据库，开发出产品。

关键词：ADO、窗体、数据库。

前 言

以最少的代价，获取最大的收益，是经济学的基本精神。但这并非表示们吝於付出，因为资源是有限的，稀少的资源，迫使们必须做选择，而管理行为就是用聪明的选择，找出代价最少、收益最大的一条路，让有限的资源得以发挥最大的功用。在生活的旅程中，们常常面临选择，在正确抉择的同时，也代表了们对环境的认知，对专业的依赖，以及对自己的信心。

对於资金的筹措及运用，管理学可以提供们最佳的策略及方法，以最少的成本取得资源，并做有效的分配，因应景气循环及环境的变化，配合目标订出适合自己的信息组合。

目 录

摘 要 ????????????????????????????? 前 言 ?????????????????????????????

第一章 绪论??????????????????????????3

一.为什么要开发一个停车场停车场车辆管理系统????????????????3

二．设计系统的必要性和可行性?????????????????4

第二章 开发环境简介 ???????????????????????

2.1 系统的开发 ???????????????????????

2.1.1 编程环境的选择 ???????????????????

2.1.2 关系型数据库的实现 ?????????????????

2.1.3 二者的结合（ADO） ??????????????????

2.2 Windows下的 Visual Basic编程环境 ????????????

2.3 使用ACCESS2000实现关系型数据库 ?????????????

第三章 系统功能分析与设计 ????????????????????

3.1 系统设计分析 ??????????????????????

3.2 系统前期设计 ??????????????????????

3.2.1 流程图 ???????????????????????

3.2.2 系统开发的设计思想??????????????????

3.3 系统功能分析 ??????????????????????

3.4 系统技术要点 ??????????????????????

第四章 系统实现 ?????????????????????????

4.1 系统功能实现 ??????????????????????

4.1.1 用户注册 ??????????????????????

4.1.2 主界面的实现 ????????????????????

4.1.3 各个模块的实现 ??????????????????? 结束语 ????????????????????????????? 致谢 ?????????????????????????????? 参考文献 ???????????????????????????? 附录一 文献综述 ????????????????????????? 附录二 英文资料 ????????????????????????? 附录三 英文资料翻译 ??????????????????????? 附录四 部分源代码 ????????????????????????

第一章 绪论

1．1为什么要开发一个停车场停车场车辆管理系统

信息作为生产力中最活跃的因素，很早就在人类经济生活中发挥着不可替代的作用，但把信息纳入企业经营管理系统中高效处理和应用是在计算机发明以后的50年代末。

目前人们所提到的管理信息系统，通常是指以计算机为工具，对管理信息进行收集、存贮、检索、加工和传递，使其应用于组织机构及企业管理领域的“人－机系统”，该系统是70年代初“后工业经济”时代的产物，在企业管理信息系统在其发展的初期，是单一的人—机系统，系统功能简单，效率低，对管理的作用有限。

进入2 0世纪80年代末，随着计算机网络和通信技术的大力发展，企业管理信息系统进入网络化的发展时期。世界发达国家已建立起了完善的先进的管理信息系统体系，在其社会经济发展领域中发挥着巨大的作用。

我国的管理信息系统大发展是在80年代末90年代初，国家相继建立起了“金卡”、“金关”、金桥“工程，多数企事业单位建立了局域网和广域网管理信息系统。随着世界经济和我国经济逐步向知识经济迈进，无论是基于工业经济的管理信息系统，还是面向少数专家和管理人员的专家系统 (ES)或决策支持系统 (DSS)，其处理对象和服务对象，自身的系统结构，处理能力，都有了进一步的发展。

停车场车辆管理（Personal Finance）并不是一个新鲜词。想想看，您是如何管理您的车辆信息的？其实您在日常生活中不自觉地运用着各种管理方法。但科学管理的前提是建立正确的管理观、正确管理科学管理的含义。

如何科学管理？

正确的管理观念非常重要，科学管理方式选择将成为决定车辆贫富差距的关键性因素。

停车场车辆管理的核心是投资收益的最大化和车辆信息分配合理化的

集合。管理服务通过充分利用各种管理工具，帮助您达到合理分配的目的、满足您对管理安全性、收益性等多样化要求。

开发一个停车场车辆管理软件迎合了现代的公司发展趋势，对居民合理管理公司和他人的联系信息起到重要意义。

1．2设计系统所要达到的要求

目标系统应该达到以下要求：

1、时间经济性。优化逻辑设计与物理设计，使系统运行效率高，反映速度快。

2、可靠性。能连续准确的处理业务，有较强的容错能力。

3、可理解性。用户容易理解和使用该系统。

4、可维护性和适应性。系统应易于修改、易于扩充、易于维护，能够适应业务不断发展变化的需要。

5、可用性。目标系统功能齐全，能够完全满足业务需求。

6、安全保密性。保证系统的物理安全、数据存储和存取的安全与保密、数据传输的安全与保密，做好使用人员的授权管理。

第二章 开发环境简介

2.1 系统的开发

2.1.1 编程环境的选择

微软公司的Visual Basic 6.0是Windows应用程序开发工具，使目前最为广泛的、易学易用的面向对象的开发工具。Visual Basic提供了大量的控件，这些控件可用于设计界面和实现各种功能，减少了编程人员的工作量，也简化了界面设计过程，从而有效的提高了应用程序的运行效率和可靠性。故而，实现本系统VB是一个相对较好的选择。

2.1.2 关系型数据库的实现

ACCESS2000 就是关系数据库开发工具，数据库能汇集各种信息以供查询、存储和检索。ACCESS 的优点在于它能使用数据表示图或自定义窗体收集信息。数据表示图提供了一种类似于 Excel 的电子表格，可以使数据库一目了然。另外，ACCESS 允许创建自定义报表用于打印或输出数据库中的信息。ACCESS也提供了数据存储库，可以使用桌面数据库文件把数据库文件置于网络文件服务器，与其他网络用户共享数据库。ACCESS 是一种关系数据库工具，关系数据库是已开发的最通用的数据库之一。如上所述，ACCESS 作为关系数据库开发具备了许多优点，可以在一个数据包中同时拥有桌面数据库的便利和关系数据库的强大功能。

2.1.3 二者的结合（ADO）

微软的JET数据库引擎提供了与数据库打交道的途径，们是通过它以及Visual Basic 来访问数据库并对其进行各种操作。Visual Basic、ACCESS以及其他微软的软件产品都是通过共用JET数据库引擎，从而给用户提供了丰富的数据类型。

ADO 控件在数据库中的信息与将信息显示给用户看的Visual Basic程序之间架起了一座桥梁。们可以设置ADO控件的各个属性，告诉它要调用那个数据库的哪个部分。缺省情况下，ADO控件根据数据库中的一个或多个数据表建立一个dynaset-type（动态集合）类型的记录集合。一个记录集合是动态的也就意味着，当原来的数据表中的容改变了以后，该记录集合中的记录也会随之改变。ADO控件还提供了用来浏览不同记录的各种跳转按钮。将ADO控件放置在窗体中之后，们还必须在该控件与要处理的数据库之间建立联系。

ADO（ActiveX Data Objects）是基于组件的数据库编程接口，它是一个和编程语言无关的COM组件系统。本文主要介绍用ADO编程所需要注意的技巧和在VC下进行ADO编程的模式，并对C＋＋Extensions进行了简单的讨论，希望对ADO开发人员有一定的帮助作用。因为ADO是一个和编程语言无关的COM组件系统，所以这里讨论的要点适用于所有的编程语言和编程环境，比如：VB、VBScript、VC、Java等等。 ADO定义了一个可编程的对象集合.ADO对象模型如图所示

:

对于ADO其中对象来说,觉得比较重要是:Command,Connection,Recordset对象。虽然严格的说这是不准确的,但根据的实际经验确实如此。下面就分别来谈一下。

①、Connection对象：

Connection对象用于建立与数据库的连接。通过连接可从应用程序访问数据 源。它保存诸如指针类型,连接字符串,查询超时,连接超时和缺省数据库这样的连接信息。

②、Command对象：

在建立Connection后,可以发出命令操作数据源。一般情况下,Command对象可以在数据库中添加,删除或更新数据,或者在表中进行数据查询。ommand对象在定义查询参数或执行一个有输出参数的存储过程时非常有用。

③、Recordset对象：

Recordset对象只代表一个记录集,这个记录集是一个连接的数据库中的表,或者是Command对象的执行结果返回的记录集。在ADO对象模型中,是在行中检查和修改数据的最主要的方法,所有对数据的操作几乎都是在Recordset对象中完成的。ecord对象用于指定行,移动行,添加,更改,删除记录。

下面就具体地说说如何用ADO存取数据,在实际编程过程中使用ADO的一个典型的存取数据的步骤为：

①、数据源

②、记录集对象

③、记录集

④、连接

2.2 Windows下的 Visual Basic编程环境

Visual Basic（简称VB）是一种可视化的、事件驱动型的Windows应用程序开发工具，它在GUI设计、绘图、制表、运算、通信和多媒体开发方面都具有简单易行、功能强大等优点，所以越来越受到开发人员的亲睐。同时，VB在数据库开发方面也具有Foxpro所远不能及的强大功能。VB能够读取和访问ACCESS、Excel、DbaseX、Foxpro、Btrieve和ODBC等多种数据库，并能利用VB自身所带的数据库引擎创建ACCESS数据库。所以VB在管理信息系统（MIS）的开发和建设方面得到了是益广泛的应用。现在，笔者就VB应用数据库的一些方法作一简单的介绍。

VB访问数据库通常有三种途径：第一，通过数据库控制控件Data Control访问；第二，通过VB提供的数据库对象变量编程访问；第三，通过ODBC接口访问ODBC API函数。在这三种方法中，第一种方法操作起来最方便、灵活、易于掌握，同时也最能体现Visual Basic面向对象的特色，故这里以Foxpro2.5的数据库为例，介绍数据库控制控件（Data Control）访问数据库的

方法与步骤：

一、 在Form窗口中加入Data Control控件

用鼠标在工具窗口的Data Control控件按钮上双击左键，该对象即出现在Form窗口的中间（控件名为Data1），用鼠标调整好控件的大小及位置。如工具箱中无此控件，可打开主菜单的Tools/Custom，在列表中选中Microsoft Data Control复选框，确认后即可将此控件加入到工具箱中去。

二、 设置联接库

用鼠标单击Data1，按下F4，打开属性窗口，设置Connect属性为Foxpro2.5，设置DatabaseName 为c:\foxprow\student.dbf（假设磁盘上已有这个文件）。

三、 加入字段显示、编辑控件（数据库捆绑控件）

在Form窗口中加入DGrid控件，如不在此控件，可打开主菜单Tools/Custom，在列表中选择Apex Data BroundGrid复选框，确认后即可向工具箱中加入此控件。在Form窗口中单击选中此控件（DGrid1），按下F4打开属性窗口，设置Datasource属性为Data1，在Form窗口中用鼠标右键单击控件DGrid1，选择 Retrieve Fields；再用鼠标右键单击控件DGrid1，选择Edit，用鼠标调整控件及有关字段大小；再用鼠标右键单击控件DGrid1，选择Properties（属性），在弹出窗口中，选择Colums标签，在下拉列表中选Colum1，将Caption属性改为“学号”，选择Colum2，Caption属性改为“姓名”，选择Colum3、4将Caption属性改为“性别”、“专业”，按下“确定”按钮。

再向Form窗口中加入一个按钮控件，将Caption属性设置为“退出”，双击该控件（Command1），在代码窗口中写入“END”，存盘。

此时，一个具备数据库读写、浏览功能的应用程序就建立了，按下F5运行，通过单击Data1的各按钮即可看出当前记录的变化情况。

2.3 使用ACCESS2000实现关系型数据库

2.3.1数据库的概念

数据库是一种存储数据并对数据进行操作的工具。数据库的作用在于组织和表达信息，简而言之，数据库就是信息的集合。计算机的数据库可以分为两类：

非关系数据库（flat-file）和关系数据库（relational）。关系数据库中包含了多个数据表的信息，数据库含有各个不同部分的术语，象记录、域等。

所谓数据库（Database）就是指按一定组织方式存储再一起的，相互有关的若干个数据的结合，数据库管理系统（Database Management System）就是一种操纵和管理数据库的大型软件，简称DBMS,他们建立在操作系统的基础上，对数据库进行统一的管理和控制，其功能包括数据库定义，数据库管理，数据库建立和维护，于操作系统通信等。DBMS通常由数据字典，数据描述语言及其编译程序，数据操纵（查询）语言及其编译程序，数据库管理例行程序等部分组成。

关系数据库是以关系模型为基础的数据库，是根据表、记录和字段之间的关系进行组织和访问的一种数据库，它通过若干个表（Table）来存取数据，并且通过关系（Relation）将这些表联系在一起，关系数据库提供了成为机构化查询语言（SQL）标准接口，该接口允许使用多种数据库工具和产品，关系数据库是目前最广泛应用的数据库。

在Visual Basic中，关系型数据库一般可以分为两类：一类是桌面数据库，例如ACCESS、Paradox、FoxPro、Dbase,另一类就是停车场车辆管理/服务器数据库，例如ACCESS、Oracle和Sybase等。

一般而言，桌面数据库主要应用于小型的、单机的数据库应用程序。也是初学者常用的数据库类型。实现起来比较方便，但同时也只能提供数据的存取功能。它主要用于小型的、单机的、单用户的数据库管理系统。

管理信息系统的数据库选用Microsoft公司的ACCESS产品作为数据库应用程序。目前的ACCESS 2000是Microsoft强大的桌面数据库平台的第六代产品，是3 2位ACCESS的第三个版本。ACCESS有以下一些基本定义：

·数据库是一个包含各种ACCESS “对象”(表、查询、窗体、报表、宏和模块)的文件，ACCESS中所有工作都是建立在此基础之上的。

·表是存放数据的容器，被设计成行和列的格式，就像电子表中的那样。每一列叫做一个“字段”，包含特定类型的信息，如姓名或学历。每一行称为一个“记录”，包含与单个实体有关的所有信息，如某个员工的姓名、性别、所在部门、学历等。对于像ACCESS这样的关系数据库管理程序，一个数据库通常包含几个存放相关数据的不同表。

·查询是一个ACCESS对象，它询问数据库中有关数据的问题。根据设计方法的不同，查询能够在数据库中检索并组合来自不同表的数据。例如，可以设计一个查询来告知在公司中工作超过1年的职员有多少。查询还可以对一组数据执行操作，如更新或删除某组记录。

·窗体是一个窗口，它提供一种很方便的途径来查看数据库中已有记录或向数据库中增添新记录。在ACCESS中，可以创建一个窗体，用来同时查阅单个表或多个表中的数据，还可以打印和显示窗体。

·报表是一个ACCESS对象，设计来显示数据，其作用类似于窗体，但主要是用于数据打印，不能输入数据。

· 页是一种特殊类型的窗体，它使用户能够利用Web浏览器查看和编辑ACCESS的表。

·宏用来保存ACCESS中的一系列操作。可自动执行一些日常的任务，以便简化在ACCESS中的工作。

· 模块是用Visual Basic for Applications(VBA) 编写的过程，VBA是ACCESS的基础程序设计语言。利用VBA可以编写程序代码来完成ACCESS宏所不能完成的特定任务。

2.3.2新建一个数据库

创建任何一个数据库的第一步是仔细的规划数据库，设计必须是灵活的、有逻辑的。创建一个数据库结构的过程被认为是数据模型设计。

①、标识需要的数据；

②、收集被标识的字段到表中；

③、标识主关键字字段；

④、绘制一个简单的数据图表；

⑤、规范数据；

⑥、标识指定字段的信息；

⑦、创建物理表。

2.3.3修改已建的数据库

数据库的修改分为：添加、编辑和删除记录。这三种操作均可由Visual Basic 创建的程序来完成，下面的章节将详细描述实现的具体方法。

2.3.4实现数据库之间的联系

数据库之间的关系指明两个库之间共享一个共同的关键字值。一个连接是指一种虚拟的表，这种表是在当用户要求从相互关联的各个不同的表中获取信息时建立的，关键字段用于在相互连接的不同表中查找匹配的记录。一个更高级的连接形式称为自连接。这种连接是指一个表被连接到它自己的一个字段，或在不同的纪录中由重复数据的组合字段。数据库中有三种不同类型的关键字：主关键字、组合关键字和外关键字。在表中使用的关键字类型用于描述库表示什么以及在数据库中如何与其它的库建立关系。

对表的行和列都有特殊的叫法，每一列叫做一个“字段”。每个字段包含某一专题的信息。就像“停车场车辆管理”数据库中，“姓名”、“联系电话”这些都是表中所有行共有的属性，所以把这些列称为“姓名”字段和“联系电话”字段。

把表中的每一行叫做一个“记录”，每一个记录包含这行中的所有信息，就像在停车场车辆管理数据库中某车辆全部的信息，但记录在数据库中并没有专门的记录名，常常用它所在的行数表示这是第几个记录。数据库的结构创建好了，接下来们需要做的就是对数据库进行一系列的基本操作。

增加记录：在“数据表”视图或“窗体”视图中打开相应的窗体，单击工具栏上的“新记录“按钮 ，键入所需数据，然后按 TAB 键转至下一个字段，在记录末尾，按 TAB 键转至下一个记录。

编辑记录：如果要编辑字段中的数据，单击要编辑的字段，如果要替换整个字段的值，指向字段的最左边，在鼠标变为加号时，单击该字段，键入要插入的文本。

注意：如果键入有错，可按 BACKSPACE 键；如果要取消对当前字段的更改，按ESC 键；如果要取消对整个记录的更改，在移出该字段之前再次按 ESC 键，当从一个记录移动到其它记录时， ACCESS 将保存对该记录的修改。

复制或移动数据：在其它应用程序，如Excel、Word中，选择要复制或移动的一至多行。如果是从Word中复制数据，应确保记录在选择之前已经在表中排列好或已经使用制表符分隔开，如果粘贴数据到数据表中，应确保数据表中的列与要复制或移动的数据的顺序一致，如果粘贴数据到窗体上，而窗体上相应的控件名称与复制数据的列名相同，ACCESS 将粘贴数据到名称相同的控件上。在ACCESS 中，打开要向其中粘贴记录的数据表或窗体，如果要替换现有记录，选择要替换的记录，然后单击工具栏上的“粘贴追加”或“粘贴”按钮 ；如果窗体中的记录选定器不可用，要选择当前记录，可单击“编辑”菜单中的“选择记录”命令。

删除记录：单击要删除的记录，单击工具栏上的“删除记录”按钮 。

2.4使用ADO数据控件访问数据库

ADO(Active Data Objects)是一种新的数据访问方式，具有以下特征： ? 有一个简化的对象模型

? 与其他Microsoft和非Microsoft技术更加紧密的集成。

? 是一个本地和远程数据访问、远程和断开连接的记录集、用户可以访问

的数据绑定接口以及层次化的记录集的通用接口。

XX人事劳资管理信息系统通过ADO这个数据控件来访问数据库，首先，安装ADO 控件要在简体中文VISUAL BASIC6.0企业版中注册后才能使用。ADO(ActiveX Data Object)是微软提出的数据访问接口，它实现了RDO的绝大多数功能，另外还增加了一些用户以前没有接触到的特征。Visual Basic 6.0可以很好地支持ADO和OLE DB数据访问模式。

在ADO2.0中包含了数据绑定、可视化设计工具以及OLE DB数据源书写模板等新的内容。在Visual Basic6.0中，ADO的数据环境设计器(Data Environment Designer)取代了Visual Basic 5.0中的RDO的用户连接设计器(User Connection

Designer)。User Connection对象只支持ODBC数据源，而Data Environment对象可以连接所有的OLE DB数据源o

ADO对象模型定义了一个可编程的分层的对象集合，它支持部件对象模型(COM)和OLE DB数据源。与其他的数据访问对象相比，包含在ADO的对象少得多，也更加容易使用。

ADO对象模型中包含了3个一般用途的对象：Connection、Command和Recordset。程序开发人员可以创建这些对象并且使用这些对象访问数据库。在ADO对象模型中还有其他几个对象，例如Field、Property、Error和Parameter，它们是作为前面3个对象的子对象进行访问的。

（1）、ADO数据控件的功能

ADO data控件使用ActiveX数据对象（ADO）来快速建立数据约束控件和数据提供者之间的连接，并快速创建记录集，然后将数据通过数据约束控件提供给用户，其中数据约束控件可以是任何具有“数据源”属性的控件，而数据提供者可以是符合OLE DB规范的数据源。使用Visual Basic的类模块也可以很方便的创建子集的数据提供者。在Visual Basic6.0中，可以使用ADO数据控件实现下面一些功能：

? 连接一个本地数据库或远程数据库。

? 打开一个指定的数据库表，或定义一个基于结构化查询语言(SQL)的查

询、存储过程或者是该数据库中表的视图的记录集合。

? 将数据字段的数值传递给数据绑定的控件，可以在这些控件中显示或更

改这些数值。

? 添加新的记录，或者根据对显示在绑定的控件中的数据的任何更改来更

新一个数据库。

（2）、ADO数据控件的属性

ADO数据控件与Visual Basic的内部数据控件(Data)和远程数据控件(RDC)很相似，它允许使用ADO快速地创建与数据库的连接。

与Data控件类似，为了实现对数据库的访问，ADO数据控件提供了几个属性，这些属性定义了怎样连接数据库以及同什么样的数据库相连接。

Connection String属性：是一个字符串，可以包含进行一个连接所需的所有

设置值，在该字符串中所传递的参数是与驱动程序相关的。例如，ODBC驱动程序允许该字符串包含驱动程序、提供者、默认的数据库、服务器、用户名称以及密码等。

ADO支持Connection String属性的4个参数，而且这4个参数将不经过ADO的处理直接送到数据源。这四个参数的属性如表3.2所示：

表3.2 Connection String属性的4个参数表

第三章 系统功能分析与设计

3.1系统设计分析

根据实际情况，们使用ADO控件少量代价快速地构造一个可执行的软件系统模型。使用户和开发人员可以较快地确定需求，然后采用循环进化的开发方式，对系统模型作连续的精化，将系统需具备的性质逐渐增加上去，直到所有的性质全部满足。此时模块也发展成为最终产品了。

3.2 系统前期设计

3.2.1 流程图

模块图

1.2.2 系统开发的设计思想

通过数据库技术分析数据库中车辆和他人的联系信息的基本信息，达到管理的目的：

①、建立数据库, 停车场车辆管理的基本资料就存放在其中。

②、把停车场车辆管理的全部资料输入数据库。

③、用VB开发出应用程序连接数据库。

④、在应用程序中用查询和统计等手段对数据库的资料进行处理，得

到有效的数据，分析出车辆的和他人的联系信息情况，得出结论和措施，然后车辆就可以通过措施达到管理的目的。

3.3 系统功能分析

系统的主要功能包括以下几方面：

①、系统登陆

需要验证密码，以防止信息被破坏。

②、车辆信息情况录入

把每日的车辆信息和收入信息登记到数据库。

③、车辆信息情况查询

对数据库中的每日的车辆信息和进行查询。

④、打印

打印出数据，可以携带出门或保存。

可以进行用户管理

设定可以进入系统的用户，防止系统数据库被破坏。

3.4数据库的结构设计

车辆信息表：车辆信息表里存储了车辆的车辆信息情况。该表主要完成停车

场车辆管理基本信息的录入、删除 、更新等功能。 车主信息表

车辆表：车辆信息表里存储了车辆的车辆合作情况。

用户表：用户表里存储了可进入数据库的用户名和密码包括：编号、姓名、密码，该表主要完成用户的增加、删除 、更新等功能。

3.6数据库与Visual Basic语言的连接

Visual Basic提供了与底层数据库系统紧密的连接。Visual Basic 支持不同的关系数据库管理系统并充分发挥每一个数据库的特长。生成独立应用或脱离服务器运行的服务以上的应用，Visual Basic连接数据库的方式有两种：

·通过使用Visual Basic的 ADO控件。

·通过使用由Visual Basic提供的专用的直接与数据库相连的接口。

3.7数据库物理设计

⒈ 确定数据的存储结构

对于这样小的系统不用考虑聚簇功能，许多关系型DBMS都提供了聚簇功能，即为了提高某个属性（或属性组）的查询速度，把在这个或这些属性上有相同值的元组集中存放在一个物理块中，如果存放不下，可以存放到预留的空白区或链接多个物理块。

2．数据的存放位置

本次设计是将数据库和程序文件放在一个文件夹，系统在启动后ACCESS数据库将自动产生一个备份文件。

第四章 系统实现

4.1 系统功能实现

4.1.1 用户登陆实现

正确输入用户名和密码，才能成功登陆用户管理系统主界面，登陆成功将显示登陆信息。

在工程引用ADO2.0。

在命令按钮单击写下连接数据库USER表的判断语句： Private Sub Command1_Click()

denlu_name = Text1.Text

denlu_pass = Text2.Text

Dim mycn As New ADODB.Connection

Dim myrs As New ADODB.Recordset

Set myrs = New ADODB.Recordset

mycn.Open "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=rsgl.mdb;" myrs.Open "SELECT * FROM [user] where (user.user)='" + denlu_name + "';", mycn, adOpenKeyset, adLockOptimistic

If myrs.BOF = True And myrs.EOF = True Then

MsgBox "查无此人", , "登陆信息"

Else

If myrs("pass") = denlu_pass Then

''''''''''''''''''''''''''''''''''''''''''

MsgBox "ok", , "登陆信息"

Form2.Show

Unload Me

''''''''''''''''''''''''''''''''''''''''''''''''''' Else

MsgBox "密码不正确", , "登陆信息"

End If

目的是USER表没有该用户，将无法使用本程序。

4.1.2 主界面的实现

用户成功登陆，随即进入主界面。

主界面包含几方面的内容,以下将做一一介绍。

4.1.3 各个模块的实现

通过ADO控件连接到数据库的RS表，通过SQL语句

筛选出全部记录，用DATA GRID控件，将它的数据源设为ADO控件，将它的各列显示出数据库的各列，属性设为可写。ADO控件，将它的各列显示出数据库的各列，属性设为可写。

通过ADO控件连接到数据库的RS表，通过SQL语句

筛选出全部记录，用DATA GRID控件，将它的数据源设为ADO控件，将它的各列显示出数据库的各列，属性设为可写。ADO控件，将它的各列显示出数据库的各列，属性设为可写。

用户查询:当使用者在主界面上电击“车辆信息查询”按钮时，将弹出车辆信息情况查询栏，该栏会供使用者进行查询，

图3-5 车辆信息情况查询

Private Sub Command1_Click()

ss = "#" & Text1.Text & "#" 将 Text1.Text赋给变量SS ss2 = "#" & Text2.Text & "#" 将 Text1.Text赋给变量SS2 Dim mycn As New ADODB.Connection 定义数据库连接 Dim myrs As New ADODB.Recordset 定义数据库记录集 Set myrs = New ADODB.Recordset

mycn.Open "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=rsgl.mdb;"

myrs.Open "delete from ls", mycn

范围符合 SS的记录

Adodc3.RecordSource = "SELECT * FROM rs where 日期 Between " + ss + " And " + ss2 + " "

Adodc3.Refresh

End Sub

然后让DATAGID表显示符合时间范围符合 SS的记录

用户管理：点击主界面上“用户管理”按钮，随即进入设定用户栏，可以查看及修改数据库人员名单，同时设定密码。

通过ADO控件连接到数据库的USER表，通过SQL语句

“SELECT user.user, user.pass FROM [user];”筛选出全部记录。 用DATA GRID控件，将它的数据源设为ADO控件，将它的各列显示出数据库的各列。属性设为可写。

Private Sub Command1_Click()

On Error Resume Next

Adodc1.Recordset.AddNew 添加记录

End Sub

Private Sub Command2_Click()

On Error Resume Next

Adodc1.Recordset.Delete 删除记录

End Sub

报表：点击主界面上“打印全部记录”按钮，随即弹出报表。报表使程序的可用性更强。

结 束 语

经过一个多月的设计和开发，系统基本开发完毕。其功能基本符合用户需求，能够完成停车场车辆管理存储和。并提供部分系统维护功能,使用户方便进行数据备份和恢复、数据删除。，对于数据的一致性的问题也通过程序进行了有效的解决。

但是由于毕业设计时间较短，所以该系统还有许多不尽如人意的地方，比如功能较少等多方面问题。这些都有待进一步改善。

在软件的编写过程中，我充分体会了软件编程工作者的辛苦，因为每一个细微的细节都必须十分的注意，如果稍有不慎，就会全盘皆输，而且往往很多的时候，程序我自己觉得非常的正确，但是就是编译通不过，在查找错误的过程中，面临着否认自己的过程，非常的痛苦，而且由于自己的经验及各方面的能力的不足，所以进展的速度非常的缓慢，往往几天的时间还没有一点进展。

在开始编写程序的时候，我看到别人的软件功能非常的详细，而且界面非常的漂亮，总希望自己的软件也非常的完善，但是，经过二个月的学习，发现编一个优秀的软件决不是一蹴而就的事情，需要长时间的积累和经验，而这个方面又是我的弱项，因此，在朋友的帮助下，我终于认清自己的不足及劣势，不要贪图大而全，只要尽我所能，编制一个实用简单的软件也是件很不容易的事情。

在反反复复的学习及虚心请教之下，我的辛勤努力有了汇报，终于做出了一个简单的软件，虽然这个软件的功能非常的简单，而且我想，在实际的运用中，肯定会有所不足，但是，它毕竟代表了我辛勤的结晶。

致 谢

由于我的知识浅薄，经验不足及阅历颇浅，因此，在该系统的设计方面还有很多不足，比如功能过少，界面不够醒目等问题，我会在工作的使用过程中，根据工作的具体要求不断的修改，完善，争取使该系统慢慢趋向完美。

在本系统的设计过程和论文编写过程中，很多老师、同事和朋友都给与了我许多无私的帮助，尤其是我的导师给我的论文提出了很多宝贵的修改意见，在这里，我向这些无私帮助我的人表示衷心的感谢。在此次毕业设计中，指导老师对

我严格要求、耐心教导，使我顺利完成了设计。并帮我将所学的知识融会贯通、综合应用。还在停车场车辆管理的理论方面给了我很多的指导，特在此表示衷心的感谢！

参考文献

[1] Bob Reselman 、Richard Peasley、Wayne Pruchniak 编著.《Visual Basic 6.0 使用指南》. 人民邮电出版社，2000/1

[2] Craig Eddy ，Timothy Buchanan 编著.《中文ACCESS 2000 24学时教程》. 机械工业出版社，2003/6

[3] 邱振崑编著.《ACCESS的应用》. 中国青年出版社,2002/3

[4] admin编著.《中文ACCESS 2000疑难解析》. 网络文件，2003/6

[5] 刘炳文编著.《Visual Basic 6.0中文版》. 电子工业出版社，2001/3

[6] 刘勇等编著.《Visual Basic 6.0程序设计实用教程》. 清华大学出版社，2004/4

[7] （美）Rick Dobson编著.《Visual Basic与ACCESS数据库开发》. 清华大学出版社，2004/3

[8] G.维克托.霍尔曼 杰利.S.诺森布鲁门 编著.《停车场车辆管理计划（第六版）》. 中国财政经济出版社，2003/8

[9] 夸克霍编著.《停车场车辆管理策划(平)》.中国金融出版社，2003/8

[10] 申莉莉编著.《数据库系统与ACCESS教程》. 清华大学出版社，2003/12

附录一 文件综述

一、《Visual Basic 6.0 使用指南》

这是一本详细讲解如何使用Visual Basic 6.0进行编程的英文原版教材。该书使用面向对象/事件驱动的Visual Basic 6.0语言，采用任务驱动的方式向学生讲解编程的概念，激发学生对于基于Windows应用程序的热情，让学生理解如何充分利用Visual Basic的强大功能，学会编写实际工作中会遇到的应用程序。书中强调了设计技巧，如访问数据库中的信息、创建与打印报表、引用对象、使用OLE等。此外，该书向学生简介了面向对象编程技术以及Visual Basic .NET的最新功能。作为教材，书中提供了大量的练习题，并提供有教辅材料，另外在随书光盘中，提供有专为本教材定制的Visual Basic 6.0软件。

二、《中文ACCESS 2000 24学时教程》

本书是中文ACCESS 2000 的自学指南。通过本书，读者可以掌握ACCESS 2000 的基本概念和操作。全书共分24学时，先介绍ACCESS 2000 的基础操作知识，然后讲述如何修改已有数据库，接下来介绍创建新数据库的方法。最后讨论一些高级主题。

三、《中文ACCESS 2000疑难解析》

本书是学习和使用ACCESS 2000 的必备书，书中列举了使用ACCESS 2000 时所遇到的常见疑难问题及解答。全书共分16章，每一章都包含了ACCESS 2000 一个特定方面的问题和解答。本书按相应的主题由浅入深地提出问题并解答，可作为学习和使用ACCESS 2000 的入门指南。(PDF格式)

四、《中文版 Visual Basic 6．0》

中文版是Microsoft公司推出的最新Visual Basic版本，它简单易学、功能强大，深受广大计算机专业人员和非专业人员的欢迎。本书通过大量实例，深入浅出地介绍了Visual Basic 6．0中文企业版的编程环境、常用内部控件的功能和用法、控制结构、数组、过程、菜单、ActiveX控件、键盘与鼠标事件过程、多窗体与环境应用、MDI、对象和集合、API、图形、多媒体、ActiveX控件的建立和DLL、HTML文档的建立以及脚本编写语言VBScript、Internet控件等。全书在编排上充分注意了由简及繁、由浅入深、循序渐进，力求通俗易懂、简捷实

用。 本书可供具有Windows 9X或Windows NT初步知识的读者自学，也可作为大专院校、培训班的教材和参考书使用。

五、《Visual Basic 6.0程序设计实用教程》

本书从入门开始，通过大量实例，系统、详细地介绍了面向对象的程序设计思想，Visual Basic 6.0程序设计的基本方法，控件的使用，文件系统的数据库的变成以及应用程序的打包发布。本书的特点是面向应用，着重培养和训练编程能力，不过多地介绍语法和算法，叙述上力求做到通俗易懂，深入浅出，所有的例题均经过上机调试运行通过，并提供了一定数量的思考题和编程练习题。书的主要内容包括Visual Basic 6.0概述，Visual Basic 6.0基本概念和基本操作，面向对象的编程方法，Visual Basic语言基础，Visual Basic6.0基本控 件，窗体、菜单、通用文件对话框的设计，文件的概念及使用，FSO文件系统， 使用ADO控件访问数据库，程序调试与错误处理，应用程序的打包与发布等。 本书可作为高职高专计算机专业或本科计算机专业的程序设计课程教材，也可做 为培训教材及自学读物。

六、《Visual Basic与ACCESS数据库开发》

●ACCESS开发人员可以使用．NET框架中的哪些功能

●Visual Basic中的数据类型、过程、循环、数组、类、类的继承、事件处理程序、结构化异常处理程序以及进程

●代码隐藏Windows Forms与使用窗体控件编程

●Form导航、Data Form Wizard以及对DataGrid控件编程

●介绍ADO的体系结构、如何对数据访问与操作进行编程，并且深入探讨ADO的数据集和父子关系

●用于浏览、操作以及处理并行；中突的Windows Form示例

●使用、创建和部署XML Web服务

本书是“微软．NET程序员系列”丛书之一，主要介绍了如何使用Visual Basic 进行ACCESS数据库编程。 本书第1章针对ACCESS开发人员遇到的问题进行论述。第2—4章介绍Visual Basic。第5～6章深入介绍Windows Forms。第7～

9章介绍使用ACCESS数据库进行ADO开发。

十、《数据库系统与ACCESS教程》

Microsoft ACCESS 2002是微软公司最新推出的一个功能强大的数据库管理系统，具有良好的应用前景。本书以一个图书管理系统实例为主线，主要介绍了数据库原理、ACCESS 2002的开发环境、创建ACCESS数据库的方法、ACCESS表的设计和创建、查询的建立及应用、窗体的设计、报表的设计、ACCESS Web页、ACCESS宏和模块，以及ACCESS数据库的安全保护知识。本书内容详实，文字简练，实例丰富，图文并茂。在介绍ACCESS 2002数据库的各方面知识和方法的基础上，突出了可读性、可操作性和实用性的写作特点。本书可用作高职高专院校计算机及其相关专业的教材，也可供数据库技术的初、中级水平读者和专业技术人员参考。

e," Calvin said. Cirocco glanced at him, got a glimpse of his brown eyes before he turned back to his work.

"That was my thought. A real big fusion ramscoop. The machinery is in the hub, electromagnetic field generators to funnel the interstellar hydrogen into the center, where it gets burned."

Gaby shrugged. "Makes sense. But what about docking?" "Well, leaving the thing would be easy enough. just drop out a hole in the bottom and get escape velocity for free, plus some to fool around with. But there ought to he some sort of dingus that would telescope out to the center of rotation when the engine isn't running, to pick up scout ships. The main engine has to he there. The only other way would be to space engines around the rim. I'd want three, at least. More would be better." nd girls' dorms, but you saw everybody in the rec room and the dining hall and so on, and she was in my psychodrama group." Her hair had been black, and shiny as the lacquered furniture in Dr. Hong's rooms, her skin white like mother-of-pearl, her eyes long and narrow (making him think of cats' eyes) and darkly blue. She was fifteen, or so Nicholas believed-maybe sixteen. "I'm going home," she told him. It was psychodrama, and he was her brother, younger than she, and she was already at home; but when she said this the floating ring of light that gave them the necessary separation from the small doctor-and-patient audience, ceased, by i

"And when I was there it rained. There was a big ,' trouble at one of the generating piles, and they shut it -_ down and it got colder and colder until everybody in the hospital wore their blankets, just like Amerinds in books, and they locked the switches off on the heaters in the bathrooms, and the nurses and the comscreen told you all the time it wasn't dangerous, they were-just rationing power to keep from blacking out the important stuff that was still running. And then it rained, just like on Earth. They said it got so cold the water condensed in the air, and it was like the whole hospital was right under a shower bath. Everybody on the top floor had to come down because it rained right on their beds, and for two nights I had a man in my room with me that had his arm cut off in a machine. But we couldn't jump any higher, and it got kind of dark."

"It doesn't always get dark here," Diane said. "Sometimes the rain sparkles. I think Dr. Island must do it to cheer everyone up."

"No," the waves explained, "or at least not in the way you mean, Diane."

Nicholas was hungry and started to ask them for something to eat, then turned his hunger in against itself, spat on the sand, and was still.es. I never met any one of his class who remembered him. They did not even remember that he was middleweight boxing champion.

I mistrust all frank and simple people, especially when their stories hold together, and I always had a suspicion that perhaps Robert Cohn had never been middleweight boxing champion, and that perhaps a horse had stepped on his face, or that maybe his mother had been frightened or seen something, or that he had, maybe, bumped into something as a young child, but I finally had somebody verify the story from Spider Kelly. Spider Kelly not only remembered Cohn. He had often wondered what had become of him.

Robert Cohn was a member, through his father, of one of the richest Jewish families in New York, and through his mother of one of the oldest. At the military school where he prepped for Princeton, and played a very good end on the football team, no one had made him race-conscious. No one had ever made him feel he was a Jew, and hence any different from anybody else, until he went to Princeton. He was a nice boy, a friendly boy, and very shy, and it made him bitter. He took it out in boxing, and he came out of Princeton with painful self-consciousness and the flattened nose, and was married by the first girl who was nice to him. He was married five years, had three children, lost most of the fifty thousand dollars his father left him, the balance of the estate having gone to his mother, hardened into a rather unattractive mould under domestic unhappiness with a rich wife; and just when he had made up his mind to leave his wife she left him and went off with a miniature-painter. As he had been thinking for months about leaving his wife and had not done it because it would be too cruel to deprive her of himself, her departure was a very healthful shock.

The divorce was arranged and Robert Cohn went out to the Coast. In California he fell among literary people and, as he still had a little of the fifty thousand left, in a short time he was backing a review of the Arts. The review commenced publication in Carmel, California, and finished in Provincetown, Massachusetts. By that time Cohn, who had been regarded purely as an angel, and whose name had appeared on the editorial page merely as a member of the advisory board, had become the sole editor. It was his money and he discovered he liked the authority of editing. He was sorry when the magazine became too expensive and he had to give it up.

By that time, though, he had other things to worry about. He had be

She turned to face the camera. "Send me what you can about hydrogen ramscoop engines," she said. "See if you can give me some idea of what to look for if Themis has one".

"You'll have to take your shirt off," Calvin said.

Cirocco reached up and switched off the camera, leaving the sound on. Calvin thumped her back and listened to the results while Cirocco and Gaby continued to study the picture of Themis. They came up with no new insights until Gaby brought UP the matter of the cables.

"As far as 1 can tell, they form a circle about midway between the hub and the rim. They support the top edges of the reflecting panels, sort of like the rigging on a sailing ship."

"What about these?" Cirocco asked, indicating the area between two of the spokes. "Any idea what they're for?"

"Nope. There's six of them, and they run midway between the spokes from the hub to the rim, radially. They pass through th fra-red, which seems to be the best spectrum."

Cirocco raised herself on one elbow, careful not to dislodge any of Calvin's electrodes. She chewed on the end of the thermometer until he frowned at her.

The print showed a fat wagon wheel surrounded by broad- based, bright red triangular areas. There were six red areas on the inside of the wheel, but they were smaller, and square.

"The big triangles on the outside are the hottest parts," Gaby said. "I figure they're part of the temperature control system. They soak up heat from the sun or bleed off the excess."

"Houston already decided that," Cirocco pointed out. She glanced at the television camera near the ceiling. Ground control was monitoring them. If they thought of something Cirocco would hear of it in a few hours, asleep or not.

The wheel analogy was almost literally true, except for the heating or cooling fins Gaby had indicated. There was a hub in the center, and it had a hole which could have taken an axle if

Themis had actually been a wagon wheel. Radiating from the hub were six thick spokes which flared gradually just before joining the outer portion of the wheel. Between each pair of spokes was one of the bright, square areas.

"This is what's new," Gaby said. "Those squares are angled. They're what 1 originally saw; the six points of light. They're flat, or they'd scatter a lot more light. As it is they only reflect light to Earth if they're at just the right angle, and that's rare."

'What kind of angle?" Cirocco - lisped. Calvin took the thermometer out of her mouth.

"Okay. Light comes in parallel to the axis, from this angle." She moved an extended finger toward the print. "The mirrors are set to deflect the light ninety degrees, into the wheel roof." She touched the paper with her finger, turned the finger, and indicated an area between two spokes.

"This part of the wheel is hotter than the rest, but not so hot that it could be soaking up all the heat it gets. It's not reflecting it or absorbing it, so it's transmitting it. It's transparent or trans- lucent. it lets most of the light go through to whatever's underneath. Does that suggest anything to you?"

Cirocco looked up from her careful examination. "What do you mean?"

"Okay. We know the wheel is hollow. Maybe the spokes are, too. Anyway, picture the wheel. It's like a car tire, big and fat and flat on the bottom to give more living space. Centrifugal force pushes you away from the hub."

"I've got all that," Cirocco said, slightly amused. Gaby could he so intense when explaining something.

"Right. So when you're standing on the inside of the wheel, you're either under a spoke, or under a reflector, right?"

"Yeah? Oh, yeah. So-" "So it's always either daytime or nighttime at any particular spot. The spokes are rigidly attached, the reflectors don't move, and neither can the skylights. So it has to be that way. Permanent day or permanent night. Why do you think they'd build it that way?"

"To answer that, we'd need to meet them. Their needs must he different from ours." She looked back at the picture. She had to keep reminding herself of the size of the thing. Thirteen hundred meters in diameter, 4000 around the outer rim. The prospect of meeting the beings who built such a thing was worrying her more each day.

"All right. 1 can wait." Gaby was not that interested in Them- is as a spacecraft. To her it was a fascinating problem in observation. en there; I'd like to know."

"I am more like Earth than Earth now is, Nicholas. If you were to take the best of all the best beaches of Earth, and clear them of all the poisons and all the dirt of the last three centuries, you would have me."

"But this isn't Earth?"

There was no answer. Nicholas walked around the ashes of the fire until he found Ignacio's footprints. He was no tracker, but the depressions in the soft beach sand required none; he followed them, his head swaying from side to side as he walked, like the sensor of a mine detector.

For several kilometers Ignacio's trail kept to the beach; then, abruptly, the footprints swerved, wandered among the coconut palms, and at last were lost on the firmer soil inland. Nicholas lifted his head and shouted, "Ignacio? Ignacio!" After a moment he heard a stick snap, and the sound of someone pushing aside leafy branches. He waited.

"Mum?" A girl was coming toward him, stepping out of the thicker growth of the interior. She was pretty, though too thin, and appeared to be about nineteen; her hair was blond where it had been most exposed to sunlight, darker elsewhere. "You've scratched yourself," Nicholas said. "You're bleeding."

"I thought you were my mother," the girl said. She was a head taller than Nicholas. "Been fighting, haven't you. Have you come to get me?" Nicholas had been in similar conversations before and normally would have preferred to ignore the remark, but he was lonely now. He said, "Do you want to go home?" "Well, I think I should, you know." "But do you want to?" "My mum always says if you've got something on the stove you don't want to burn-she's quite a good cook. She really is. Do you like cabbage with bacon?" "Have you got anything to eat?" "Not now. I had a thing a while ago" "What kind of thing?" "A bird." The girl made a vague little gesture, not looking at Nicholas. "I'm a memory that has swallowed a bird." "Do you want to walk down by the water?" They were moving in the direction of the beach already.

"I was just going to get a drink. You're a nice tot." Nicholas did not like being called a "tot." He said, "I set fire to places." "You won't set fire to this place; it's been nice the last couple of days, but when everyone is sad, it rains." Nicholas was silent for a time. When they reached the sea, the girl dropped to her knees and bent forward to drink, her long hair falling over her face until the ends trailed in the water, her nipples, then half of each breast, in the water. "Not there," Nicholas said. "It's sandy, because it washes the beach so close. Come on out here." He waded out into the sea until the lapping waves nearly reached his armpits, then bent his head and drank.

"I never thought of that," the girl said. "Mum says I'm stupid. So does Dad. Do you think I'm stupid?" Nicholas shook his head: "What's your name?" "Nicholas Kenneth de Vore. What's yours?"

"Diane. I'm going to call you Nicky. Do you mind?"

"I'll hurt you while you sleep," Nicholas said.

"You wouldn't." "Yes I would. At St. John's where I used to be, it was zero G most of the time, and a girl there called me something I didn't like, and I got loose one night and came into her cubicle while she was :`r asleep and nulled her restraints, and then she floated around until she banged into something, and that woke her up and she tried to grab, and then that made her bounce all around inside and she broke two fingers and her nose and got blood all over. The attendants came, and one told me-they didn't know then I did it-when he came out his white suit was, like, polka-dot red all over because wherever the blood drops had touched him they soaked right in."

The girl smiled at him, dimpling her thin face. "How did they find out it was you?" "I told someone and he told them." "I bet you told them yourself." "I bet I didn't!" Angry, he waded away, but when he had stalked a short way up the beach he sat down on the sand, his back toward her. "I didn't mean to make you mad, Mr. de Vore." "I'm not mad!" She was not sure for a moment what he meant. She sat down beside and a trifle behind him, and began idly piling sand in her lap. Dr. Island said, "I see you've met." Nicholas turned, looking for the voice. "I thought you saw everything." "Only the important things, and I have been busy on another part of myself. I am happy to see that you two know one another; do you find you interact well?" Neither of them answered. "You should be interacting with Ignacio; he needs you." "We can't find him," Nicholas said. "Down the beach to your left until you see the big stone, then turn inland. About five hundred meters." Nicholas stood up, and turning to his right, began to walk away. Diane followed him, trotting until she caught up. "I don't like," Nicholas said, jerking a shoulder to indicate something behind him. "Ignacio?" "The doctor." "Why do you move your head like that?" "Didn't they tell you?" "No one told me anything about you." "They opened it up"-Nicholas touched his scars" and took this knife and cut all the way through my corpus . . . corpus . . ." "Corpus callosum," muttered a dry palm frond. "-corpus callosum," finished Nicholas. "See, your brain is like a walnut inside. There are the two halves, and then right down in the middle a kind of thick connection of meat from one to the other. Well, they cut that."

"You're having a bit of fun with me, aren't you?" "No, he isn't," a monkey who had come to the water line to look for shellfish told her. "His cerebrum has been surgically divided; it's in his file." It was a young

monkey, with a trusting face full of small, ugly beauties.

Nicholas snapped, "It's in my head."

Diane said, "I'd think it would kill you, or make you an idiot or something." "They say each half of me is about as smart as both of us were together. Anyway, this half is . . . the half . . . the me that talks." "There are two of you now?" "If you cut a worm in half and both parts are still alive, that's two, isn't it? What else would you call us? We can't ever come together again." "But I'm talking to just one of you?" "We both can hear you." "Which one answers?" Nicholas touched the right side of his chest with his right band. "Me; I do. They told me it was the left side of my brain, that one has the speech centers, but it doesn't feel that way; the nerves cross over coming out, and it's just the right side of me, I talk. Both my ears hear for both of us, but out of each eye we only see half and half-I mean, I only see what's on the right of what I'm looking at, and the other side, I guess, only sees the left, so that's why I keep moving my head. I guess it's like being a little bit blind; you get used to it."

The girl was still thinking of his divided body. She said, "If you're - only half, I don't see how you can walk." "I can move the left side a little bit, and we're not mad at each other. We're not supposed to be able to come together at all, but we do-down through the legs and at the ends of the fingers and then back up. Only I can't talk with my other side because he can't, but he understands."

"Why did they do it?" Behind them the monkey, who had been following them, said, "He had uncontrollable seizures."

"Did you?" the girl asked. She was watching a sea bird swooping low over the water and did not seem to care.

Nicholas picked up a shell and shied it at the monkey, who skipped out of the way. After half a minute's silence he said, "I had visions."

"Ooh, did you?"

"They didn't like that. They said I would fall down and jerk around horrible, and sometimes I guess I would hurt myself when I fell, and sometimes I'd bite my tongue and it would bleed. But that wasn't what it felt like to me; I wouldn't know about any of those things until afterward. To me it was like I had gone way far ahead, and I had to come back. I didn't want to."

The wind swayed Diane's hair, and she pushed it back from her face. "Did you see things that were going to happen?" she asked.

"Sometimes."

"Really? Did you?"

"Sometimes."

"Tell me about it. When you saw what was going to happen."

"I saw myself dead. I was all black and shrunk up like the dead stuff they cut off in the 'pontic gardens; and I was floating and turning, like in water but it wasn't water-just floating and turning out in space, in nothing. And there were lights on both sides of me, so both sides were bright but black, and I could see my teeth because the stuff"-he pulled at his cheeks" had fallen off there, and they were really white."

"That hasn't happened yet."

"Not here."

"Tell me something you saw that happened" Men Without Women

Ernest Miller Hemingway was born in 1899 at Oak Park, a highly respectable suburb of Chicago, where his father, a keen sportsman, was a doctor. He was the second of six children. The family spent holidays in a lakeside hunting lodge in Michigan, near Indian settlements. Although energetic and successful in all school activities, Ernest twice ran away from home before joining the Kansas City Star as a cub reporter in 1917. Next year he volunteered as an ambulance driver on the Italian front and was badly wounded. Returning to America he began to write features for the Toronto Star Weekly in 1919 and was married in 1921. That year he came to Europe as a roving correspondent and covered several large conferences. In France he came into contact with Gertrude Stein�Xlater they quarreled�XEzra Pound, and James Joyce. He covered the Greco-Turkish war in 1922. Three Stories and Two Poems was given a limited publication in Paris in 1923. Thereafter he gradually took to a life of bull-fighting, big-game hunting, and deep-sea fishing. He visited Spain during the Civil War. Latterly he lived mostly in Cuba, and he died in July 1961.

He early established himself as the master of a new, tough, and peculiarly American style of writing and became a legend during his lifetime. But, as John Wain wrote in the Observer after his death, ¨Though there were many imitators there was never truly a ˉSchool of Hemingwayˇ, because the standard he set was too severe.〃

His best-known books were A Farewell to Arms (1929), Death in the Afternoon (1932), For Whom the Bell Tolls (1940), and The Old Man and the Sea (1952). In 1954 he was awarded the Nobel Prize for Literature. Ernest Hemingway had three sons.

Robert Cohn was once middleweight boxing champion of Princeton. Do not think that I am very much impressed by that as a boxing title, but it meant a lot to Cohn. He cared nothing for boxing, in fact he disliked it, but he learned it painfully and thoroughly to counteract the feeling of inferiority and shyness he had felt on being treated as a Jew at Princeton. There was a certain inner comfort in knowing he could knock down anybody who was snooty to him, although, being very shy and a thoroughly nice boy, he never fought except in the gym. He was Spider Kelly's star pupil. Spider Kelly taught all his young gentlemen to box like featherweights, no matter whether they weighed one hundred and five or two hundred and five pounds. But it seemed to fit Cohn. He was really very fast. He was so good that Spider promptly overmatched him and got his nose permanently flattened. This increased Cohn's distaste for boxing, but it gave him a certain satisfaction of some strange sort, and it certainly improved his nose. In his last year at Princeton he read tooe reflects panels, if that tells you anything."

"Not exactly. But if there's any more of these things, maybe smaller ones, we should look for them. These cables are about- what did you say? Three kilometers around?"

"More like five."

"Okay. So one that's just a tiny thing-say about as big around as ringmaster-might be invisible to us for a long time, especially if it's as black as the rest of Themis. Gene's going to be nosing around there in the SEM. I'd hate for him to hit one."

"I'll get the computer on it," Gaby said. Calvin began packing his equipment.

"As disgustingly healthy as usual," he said. "You people never give me a break. If 1 don't try out that five-million-dollar hospital how am 1 going to make them believe they got their money's worth?" "You want me to break somebody's arm?" Cirocco suggested.

"Nah. I already did that, back in medical school."

"Broke one, or fixed it?"

Calvin laughed. "Appendix. Now there's something I'd like to try. You don't hardly get busted appendixes anymore."

"You mean you've never taken out an appendix? What do they teach you in medical school these days?"

"That if you get the theory right, the fingers will follow. We're too intellectual to get our hands dirty." He laughed again, and Cirocco could feel the thin wall