The Oracle tutorial you are looking at is the implementation of a dynamic Web database for Oracle components. [Abstract] This article briefly introduces the basic methods of implementing a Web database, discusses the basic method of implementing a dynamic Web using one of Oracle's server options webserver combined with pl/sql and related built-in packages, and gives a simple example.
With the development of computer interconnection network, the Internet is becoming one of the main ways of exchanging information around the world. As an important part of the Internet, the Global Information Network www (World Wide Web) uses HTML form to organize information and carry out various information integration and transfer in the way of hyper-link, which has the characteristics of friendly interface and simple operation. Users can directly use the Web browser for easy browsing, querying a variety of information. Therefore, as a window for organizations and enterprises to display information, the amount and function of the Web server can directly affect their own image and customer access.
In a traditional Web server, text and other information are stored and managed in the form of files, and the pages provided to the user's browser are mostly static. When a user enters the URL of an HTML document in a browser, it accesses a file on the webserver that changes content only if a network administrator places a new file with the same name on the Web server. With the development of WWW application field, static Web pages are increasingly unable to meet the dynamic, real-time and interactive requirements of information services, which requires the combination of database technology and WWW to achieve efficient access to data resources.
1. Using Oracle webserver to build Web database application
Oracle 8 Server is a complete information management environment. It is a repository of large amounts of data and provides users with fast access to these data. It can support C/s structure for distributed processing and Web computing. Webserver, which utilizes one of its server options, can provide powerful functionality to implement Web database applications.
Generally speaking, the implementation of Web database application can provide CGI/API and other middleware to connect webserver and DB Server on the webserver side, also can let the user download the related application through the Web browser to the client run, access the database directly on the client, such as Java Applet,active x,plug-in and so on. This article mainly introduces the use of Oracle 8 Pl/sql and its powerful built-in package to write programs to achieve dynamic Web applications. belong to the use of middleware development of a. The middleware is responsible for managing communication between Webserver and DBServer and providing application services that can directly invoke external programs or scripting code to access the database, so you can provide dynamic HTML pages related to the database, or execute user queries, The query result is formatted as an HTML page and then returned to the user's browser via webserver. Its general structure is shown below:
Web browser ←→internet←→web server←→cgi/api←→oracle DB Server
2, Pl/sql
Oracle, starting with version 6, supports a process-processing language pl/sql as a standard programming language for all Oracle tools, enabling all process components to be implemented in Oracle server products. The following important functions can be achieved with Pl/sql:
A stored procedure, that is, a program (or code snippet) that is stored in an Oracle database and completes specific important tasks for your organization;
Database triggers, that is, the code stored in the database, can be triggered by the events generated by the application;
A package, that is, the code that combines multiple processes together as a single program unit is stored in the database.
The built-in packages are pre generated, stored in a database, and can be invoked in a Pl/sql code block to pass a parameter on demand. It can output the result directly to the terminal window, read and write data directly from the operating system file, execute dynamic SQL and many other functions. Commonly used, such as Htp,htf,owa-util. The following is an example of a dynamic online query score to illustrate its application in the Dynamic Web.
