PL/SQL DBMS_XMLPARSER.PARSE

The DBMS_XMLPARSER package in Oracle PL/SQL provides a set of procedures for working with XML data, where one of the key functionalities is the PARSE procedure. This procedure allows for the parsing of XML data, enabling you to work with XML documents within your Oracle database applications effectively. The PARSE procedure is part of the Oracle XML DB, which integrates XML data management with relational database features.

Overview of DBMS_XMLPARSER.PARSE

The DBMS_XMLPARSER.PARSE procedure takes an XML document as input and parses it, creating an internal DOM (Document Object Model) representation that can be manipulated through the DOM API provided by Oracle. This enables the extraction, manipulation, and insertion of XML data within an Oracle database.

Syntax

The basic syntax for the PARSE procedure in DBMS_XMLPARSER is as follows:

DBMS_XMLPARSER.PARSE(parser IN OUT NOCOPY dbms_xmlparser.parser, xmltext IN CLOB);

parser: This is the parser object that will perform the parsing operation. It must be initialized before calling the PARSE procedure.
xmltext: This is the XML document (as a CLOB) that you want to parse.

Example

Here’s a simple example of how to use DBMS_XMLPARSER.PARSE:

Initialize the Parser

First, you need to create and initialize a parser object.

DECLARE
  l_parser dbms_xmlparser.parser;
BEGIN
  l_parser := dbms_xmlparser.newParser;

Parse the XML Document

Next, parse an XML document using the parser object.

  dbms_xmlparser.parse(l_parser, 'Value');

Work with the DOM Document

After parsing, you can work with the DOM document, like extracting data, modifying the document, etc.

  -- Example: Getting the DOM document
  DECLARE
    l_doc dbms_xmldom.domdocument;
  BEGIN
    l_doc := dbms_xmlparser.getDocument(l_parser);
  -- Additional operations on l_doc

Free the Parser

Finally, it’s a good practice to free the resources associated with the parser once you’re done.

  dbms_xmlparser.freeParser(l_parser);
END;

Considerations

Performance: Parsing large XML documents can be resource-intensive. Consider the size of your XML documents and the performance implications for your database.

Security: Ensure that the XML data you parse is secure and free from malicious code, especially if the XML content comes from untrusted sources.

Compatibility: The DBMS_XMLPARSER package and its features, including PARSE, are available in specific versions of Oracle Database. Check your database version for support and any version-specific behavior.

The DBMS_XMLPARSER.PARSE procedure is a powerful tool for handling XML data within Oracle databases, offering a way to parse and manipulate XML documents efficiently.