Tutorials XMLThe main function of an XML parser is to parse and also validate the XML document and builds an info set data structure in the memory, the functions also include manipulating the info set and then write the same data back into the XML document. The PL/SQL applications can gain access to the XML parser by using the functions called xmlparser and xmldom. Java applications provide default access to java classes. The XML documents enable the transformation into various XML document types or other formats of file using the XSLT. The PL/SQL will let you access the XSLT only when there is XSLT processor package.
You can also use something called oraxsl program to transform directly form the command line. All you have to do is give the name from the command line and give the name of the XML document that has to be transformed and a description about the style sheet which will transform and a file name for the output file. The same file can be used to transform many more documents in batches from the script.
The XDK also uses the Xpath engine because the XML parser and the XSLT processor which are an integral part of the XXDK use the Xpath engine. Functions like calling the XMLDOM in a PL/SQL package for example is the job of the Xpath engine and typically the users do not have to interact with the XML developer's kit Xpath engine.
For XML data to be published the X sequel provides a wide platform and an extensible framework. This facility is only available in the Java programs and not in Oracle. The XSQL page facility is inbuilt with the XSQL page processor and an XSQL servlet and also includes a program that will run directly from the command line. The servlet can also run with Apache, the Oracle 9i database. The command line program and the java servlet both call for the XQL page.
Publishing data has become very easy since the XSQL pages have been introduced. XML documents can be easily created using the XSQL document type data. The document also has the capability to encapsulate the data and SQL queries; it also can efficiently identify all the parameters that are passed through as a URL or even command line arguments. When the command line is used in the program the servlet is called and the query also is executed. Then the results of the query are then converted into XML.
The XML SQL utility is used to further simplify the loading and the retrieving activity of XML documents when the tables, rows and columns are used from the table, which are in turn used to represent the various segments of the XML document. An XML document is well structured can be passed to the XML SQL utility and the function of this utility is to insert the rows inside the database table.
Queries can also be submitted into the XML document which will be formatted into the document using this function. The XSLT can also be used after the querying is over or before the querying starts that the inputs can be made and the outputs turn out to be more flexible. This utility also includes the facility to update and delete the data in the database so that the XML SQL utility can be used.
Java API and the PL/SQL API are used to call the XML SQL utility from the command line. In the PL/SQL environment the XML SQL will appear like packages which are also called the DBMS or the data base management service Xml query or the data base management Service XML slave. This command can be invoked using the Java and Oracle XML. On the whole the concept which underlies the XML and its functions when associated with various programming languages and environments are all very simple.
The simple tools associated with the XML can make complex programs and complex networks run effortlessly. After Microsoft even Oracle has realized the true capabilities of XML and has jumped into the bandwagon along with Microsoft that it can harness all the goodness that XML has to offer. Every variation of Oracle and all the latest versions have unspoken bias to XML and are automatically inbuilt with the XML enabled components.
First Page: Working with XML in Oracle
