：PROJECT 2000 Tutorial

Author: Astronaut Press
:
: 2002-02-01
Features: Introduction This book is one of the unified teaching materials compiled by Microsoft Authorized Training Centers and serves as a tutorial for learning and mastering the new visual database system Visual FoxPro 6.0. With Visual FoxPro 6.0, most of the design work users perform will be immediately reflected on the screen, and users can start the program at any time to observe the results. Visual FoxPro 6.0 provides users with various rich and feature-rich wizards and generators. Through nine chapters and numerous examples, this book comprehensively and meticulously introduces the usage of Visual FoxPro 6.0. The narrative begins with an introduction to Visual FoxPro 6.0 programming for beginners, guiding readers into the application of the Visual FoxPro development environment, the design of databases and tables, the use of queries and views, the design of forms and applications, as well as the design of reports and labels, menus and toolbars, help files, and OLE extension functions. In the appendix, reference materials for using Visual FoxPro 6.0 are provided for easy consultation by readers at any time. Rich illustrations, fluent language, and detailed explanations are the greatest features of this book. In addition to serving as the unified teaching material for Microsoft Authorized Training Centers, this book is also a valuable reference for professionals involved in the Chinese version of Visual FoxPro 6.0 application and development. It is also a self-study and teaching reference book for students and teachers in relevant disciplines of colleges and universities, as well as a teaching material for training courses in related fields. Excerpt: At this stage, designers need to convert the identified requirements into a corresponding system architecture, where each component of the structure is a clearly defined module, with each module corresponding to certain requirements. This is called conceptual design. The specific description of the work to be completed by each module lays the foundation for program development, which is detailed design. All design considerations should be described in detail in the form of a design specification to facilitate subsequent work and submission for review. 4) Coding, which means writing programs. At this stage, the software design is converted into a program acceptable to the computer, i.e., written as a "source program list" in a certain programming language. 5) Testing. At this stage, testing is used to check the correctness of the various components of the software, which is also an important means of ensuring software quality. First, unit testing is performed to identify problems in the functionality and structure of the modules. Then, the tested modules are assembled for integration testing. Finally, according to the specified requirements, effective testing is conducted to determine whether the developed software meets the criteria and can be delivered to users. 6) Maintenance. After the software is formally put into use, it enters the maintenance stage. During operation, the software may encounter errors due to various reasons and need to be modified promptly. Additionally, due to changes in the external environment, the software may also need to be updated accordingly. 1.1.2 The Process of Developing a Visual FoxPro Application A Visual FoxPro application is typically composed of the following parts: one or more databases, a main program for setting the application system environment, and a user interface (such as forms, toolbars, and menus). Additionally, it may include queries and reports, which allow users to retrieve or output their data. (1) Getting Started After planning the components needed for the application, you may want to create a directory structure and a project to organize the component files for the application. At this point, you can create a directory structure in "Windows Explorer" or a project in "Project Manager," or use the "Application Wizard" to create both simultaneously. After the "Wizard" completes its work, you can further organize the project and components using the "Project Manager" or other Visual FoxPro designers. (2) Using the "Project Manager" The "Project Manager" can compile the completed application. Additionally, during the development phase, it makes it easier to design, modify, and run certain components of the application. The "Project Manager" provides the following features: Double-click an application component (form, menu, program) to run or modify it. Drag classes, tables, or fields directly from the "Project Manager" into the "Form Designer" or "Class Designer." Drag classes between class libraries. Easily view and modify your tables. Add descriptions to your application components. Drag and drop various entries between projects. (3) Creating Databases Since database applications heavily rely on the data they manage, it is best to start with the data when designing the application. Before designing the user interface and components for managing data, set up the database, determine the relationships between tables, and identify the desired transaction rules, etc. With a reliable database foundation, development work will become much easier. Specifically, when determining the database structure, the following points should be considered. (a) User operations Since the way users process information will determine how the application handles data, users should also focus on this aspect when designing the database structure. (b) Database size When dealing with large data sets, performance improvement should be considered. Sometimes, you may need to adjust the way users navigate between data. For example, if a table contains only twenty or thirty records, moving the record pointer one record at a time will not be a problem. However, if the table contains twenty or thirty thousand records, you must provide users with other methods to find all the data (such as adding search lists, dialog boxes, filters, and custom queries). (c) Single-user and multi-user When creating applications, it is best to consider the scenario where multiple users access the database simultaneously. Visual FoxPro provides some technologies that make it easy for users to perform shared access programming. (d) Internationalization considerations If you know in advance that the application will only be used in a single-language environment, you may not need to consider internationalization issues. However, if you want to expand the market or if users need to handle internationalized data and environment settings, you should consider these factors when creating the application.