PL/SQL Gateway in R11i



Last updated on November 28th, 2015 at 11:55 am

The PL/SQL Gateway in R11i provides support for building PL/SQL-based applications on the Web.

– PL/SQL stored procedures can retrieve data from a database and generate HTTP responses containing data and code to display in a Web browser.
– Also can upload/download file to datbase table from browser and access that file from the browser.
– also supports Oracle Portal.

Processing Client Requests :

It uses mod_plsql (an Apache module) used to communicate with the database. It maps browser requests into database stored procedure calls over a SQL*Net connection. It is generally indicated by a /pls virtual path.

1. The Oracle HTTP Server receives a PL/SQL Server Page request from a client browser.
2. The Oracle HTTP Server routes the request to the PL/SQL Gateway.
3. The request is forwarded by the PL/SQL Gateway to the Oracle Database. By using the configuration information stored in your DAD, the PL/SQL Gateway connects to the database.
4. The PL/SQL Gateway prepares the call parameters, and invokes the PL/SQL procedure in the application.
5. The PL/SQL procedure generates an HTML page using data and the PL/SQL Web Toolkit accessed from the database.
6. The response is returned to the PL/SQL Gateway.
7. The Oracle HTTP Server sends the response to the client browser.

The PL/SQL Gateway includes the PL/SQL Web Toolkit, a set of packages (also called the owa packages) that you can use in your stored procedure to get information about the request, construct HTML tags, and return header information to the client.

PL/SQL Gateway Configurations:
Database Access Descriptor (DAD) :
-a set of configuration values used for database access. A DAD specifies information such as:
o the database alias
o a connect string if the database is remote.
o Username and password :
o a procedure for uploading and downloading documents.
o others
To invoke the PL/SQL Gateway in a Web browser, input the URL in the following format:
protocol://hostname[:port]/prefix/DAD/[[!][schema.][package.]proc_
name[?query_string]]

– prefix (pls) : A virtual path to handle PL/SQL requests i.e. set pls as the prefix so that all requests containing the pls prefix are routed to the PL/SQL Gateway.
– DAD: here its patching
– ! character (optional): Indicates to use the flexible parameter passing scheme
– proc_name : The PL/SQL stored procedure to run. This must be a procedure and not a function. It can accept only IN arguments.

 

plsql gateway is not enabled in R12.


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