What is Oracle Application Express?

Oracle Application Express is a hosted declarative development environment for developing and deploying database-centric Web applications. Thanks to built-in features such as user interface themes, navigational controls, form handlers, and flexible reports, Oracle Application Express accelerates the application development process.

The Application Express engine renders applications in real time from data stored in database tables. When you create or extend an application, Oracle Application Express creates or modifies metadata stored in database tables. When the application is run, the Application Express engine then reads the metadata and displays the application.

To provide stateful behavior within an application, Oracle Application Express transparently manages session state in the database. Application developers can get and set session state using simple substitutions as well as standard SQL bind variable syntax.

The sections that follow describe key features of Oracle Application Express.

Reporting

With Oracle Application Express, you can quickly generate HTML reports that display the results of SQL queries. You can also download and print reports in HTML, Adobe Portable Document Format (PDF), Microsoft Word Rich Text Format (RTF), and Microsoft Excel (XLS) formats.

You can declaratively link reports together to provide drill-down reporting and use bind variables to pass information from session state to a report. Reports support declarative column heading sorting, control breaks, sums, and pagination. Report sorting and pagination can use Partial Page Refresh (PPR) technology to avoid refreshing the entire page. You can also add declarative links to a report to download the report data to CSV or XML formats. Plus, you can customize the report appearance using templates. See "About Bind Variable Syntax" and "Creating Reports".

Forms

Using wizards, you can easily create forms on tables or on a stored procedure. For example, when creating a form on a table, these wizards provide automatic management of insert, update, and delete as well as lost update detection. Once you create a form, you can rearrange form fields (called form items) using a visual representation, enabling you to quickly achieve the layout you want. Form items offer a variety of display options including text fields, text areas, radio groups, select lists, check boxes, date pickers, and popup list of values. See "Creating Forms".

Charting

You can also use wizards to create HTML, SVG, or Flash charts. You can create charts that enable users to drill down from one chart to another chart or report. Charts can also be refreshed using Partial Page Refresh (PPR) technology, avoiding the need to refresh an entire page. You can also configure a chart to refresh at defined intervals. Additionally, you can take advantage of report column templates to add simple HTML bar charts to any report. See "Creating Charts".

Spreadsheet Upload

Use the Create Application from Spreadsheet Wizard to quickly upload spreadsheet data directly into the database. You can choose to store the data in a new database table or add it to an existing database table. Once the data is uploaded, you can quickly create an application. This handy wizard enables you to go from spreadsheet to a shared application in just a few clicks. See "About the Create Application from Spreadsheet Wizard".

Session State Management

Oracle Application Express transparently manages session state (or application context) in the database. Forms automatically save session state, remembering your application context over your session. Referencing session state within SQL and PL/SQL is as simple as using bind variables. For example, consider the following SELECT statement:

SELECT * FROM EMP WHERE EMPNO = :P1_ID

In this example, the value in the item P1_ID is automatically bound when the query is run. You can also reference session state within a static context by prefixing the item name with an ampersand (&) and suffixing it with a period(.), for example:

&P1_NAME.

For management of two dimensional data sets, Oracle Application Express provides a robust collections infrastructure. Best of all, session management is stateless and does not consume any memory. See "Managing Session State Values" and "About Bind Variable Syntax".

User Interface Themes

Oracle Application Express separates presentation (or user interface themes) from the application logic. You can design your application in one theme, change to another supplied theme, or create and use your own custom theme. By separating the application logic (such as queries, processes, and branches) from the HTML rendering, your application can take advantage of new designs and other technological advances without an application rewrite. See "Managing Themes".

Flow Control and Navigation

Every Web application needs navigation and dynamic applications need flow control. Oracle Application Express provides built-in components to simplify the development and maintenance of navigational controls. Navigation is controlled using declarative tabs (one or two levels), breadcrumbs, tree controls, and lists of links. Flow control is performed using declarative branches which can take effect at specific events and under certain conditions. The appearance of navigation controls are managed through templates, making it easy to change from one look to another. See "Adding Navigation" and "Controlling Navigation Using Branches".

Conditionality on All Components

When creating dynamic Web applications, many application components and processing are conditional. In other words, you only show or process certain pieces of information based on the application context, the data, an event, or a privilege. Oracle Application Express enables you to declaratively specify conditionality of all components. This gives you exact control over what users see or do not see on a tab, button, item, list entry, and so. See "Understanding Conditional Rendering and Processing".

External Interfaces and Extensibility

Even though Oracle Application Express provides a robust declarative environment for building applications, you also have the option of developing custom interfaces or controls. For example, if a component does not meet the needs of your environment, you can generate your own custom HTML using PL/SQL. See "Rendering HTML Using Custom PL/SQL". You can also call external services using Web services. See "Implementing Web Services". Oracle Application Express also includes APIs to easily integrate email alerts into an application. See "Sending Email from an Application". Plus, because Oracle Application Express resides in the Oracle database, you can take advantage of inherent database capabilities, including external tables, PL/SQL, database links, gateways, and database Java to extend the functionality of your application.

Security

With Oracle Application Express, you can create public applications that do not require a user log in, or you can create secure applications that require authentication. Oracle Application Express provides a number of built-in authentication schemes including Single Sign On, Database Account Credentials, and an easy-to-use user management system. You can also use custom schemes that interface with just about any authentication service including Microsoft Active Directory and Oracle Applications.

Additionally, you can customize authorization to meet the needs of your environment and apply authorization selectively to an entire application, a page, or a page component. Finally, you can also take advantage of an innovative session state protection feature to prevent URL tampering and built-in features to protect an application form SQL Injection and cross-site scripting (XSS) attacks. See "Managing Application Security".

SQL Workshop Tools

SQL Workshop provides tools to enable you to view and manage database objects from a Web browser. Use SQL Commands to run SQL and PL/SQL statements. See "Using SQL Commands". Query Builder enables you to define queries by dragging and dropping tables and easily create relationships between objects. See "Building Queries with Query Builder". Object Browser provides an easy-to-use graphical user interface for viewing, creating, modifying, browsing, and dropping database objects. See "Managing Database Objects with Object Browser". Finally, you can use SQL Scripts to create, edit, view, run, and delete script files. See "Using SQL Scripts".

Supporting Objects Utility

You can simplify the steps needed to export, install, upgrade, and deinstall an application in another Oracle Application Express instance by creating a packaged application. Using the Supporting Objects utility, you can bundle the application definition with scripts for creating the database objects, seed data, images, cascading style sheets, and JavaScript.

Creating a packaged application provides application users with an installer-like experience and automates the process of importing and installing an application in another development, test, or even production instance. See "How to Create a Packaged Application".

Performance

Oracle Application Express provides application developers and application users with an extremely high level of performance. Because Oracle Application Express resides in the Oracle database, it has minimal impact on network traffic. Plus, Application Builder includes a large number of monitoring reports to enable you to identify and tune application performance. See "Debugging an Application".

Hosted Development

Oracle Application Express enables a single database to host large numbers of users. Users work in a dedicated work area called a workspace. A workspace is a virtual private database that enables multiple users to work within the same Oracle Application Express installation while keeping their objects, data and applications private. This flexible architecture enables a single database instance to manage thousands of applications.

You determine how the process of provisioning (or creating) a workspace works. For example, in email verification provision mode, users request a workspace using a link on the login page. After the workspace request has been granted, users receive an email containing a link that they must click to verify the validity of their email address. Then they receive an email with their login credentials. To see an example of email verification provision mode, go to:

http://apex.oracle.com

See "Configuring Your Oracle Application Express Environment" and "Managing an Oracle Application Express Hosted Service" .