# XML - Managing Data Exchange/XML and JDBC

## Overview

ODBC is the acronym for the oft used API Open Database Connectivity.
Many applications and application programmers use ODBC in order to
access relational databases, such as SQL and Microsoft Access, and to
manipulate the data within the databases. Specifically, JDBC (Java
Database Connectivity), which is based on ODBC, is the API used by
applications developed in Java to perform these various tasks. Moreover,
JDBC is now capable of handling advanced datatypes in SQL which in turn
becomes useful when dealing with XML. Also, JDBC has within it the
ability to actually create XML data. Furthermore, the use of JAXP (Java
API for XML Processing) along with JDBC provides yet another way of
manipulating and using relational databases and XML. In any event, there
are multiple ways to use the JDBC API with XML.

## JDBC and XML Documents

Many Java Applications written today will more than likely interact with
an SQL database (or a relational database, but for the sake of
uniformity, we will work with SQL.) Depending on the intent of the
application, there may be the case of actually storing an XML document
for display or for manipulation. Whatever the case, JDBC now supports
all datatypes defined in the SQL:1999 specification. One of theses
datatypes is the CLOB (character large object) datatype. This datatype
is perfect for storing XML documents. This is one way XML and the JDBC
API works with each other.

## JDBC and XML Production

One of the more interesting things about JDBC is that it can be used to
gather MetaData. Meta-data is nothing more than data about data. From an
XML standpoint, this is very useful because we can create XML data on
the fly with nothing more than a table name. The class that makes this
possible is java.sql.ResultSetMetaData. Consequently this class is a
part of the JDBC API.

## JDBC and JAXP

Another intriguing way of dealing with XML objects is within the JAXP
(Java API for XML Processing). JAXP and JDBC together provide an
infrastructure for developing applications using XML and SQL.

Whenever XML instances in applications are dealt with, an XML parser is
a good tool to use. The XML parser turns the XML document into an object
or something the application can uses. Specifically, Document Object
Model (DOM) takes and XML instance and converts it into a tree. This
specific parser can be found in the JAXP API. You may then store the
parsed object in an SQL database for future use. This may open up many
ideas of how one may use JAXP and JDBC together when an issue presents
itself of dealing with XML and SQL.

## References

-   <http://www.xml.com>
-   <http://java.sun.com/xml>
-   Stels XML JDBC
    driver - JDBC driver
    for XML files.

