Gaining and keepingcompetitive advantage through J2EE and XML interoperability

Dimitri MaesfranckxProduct Manager

Content

Reality Database vendors Introduction Application Scenario Builder Query Example Features Key Advantages Q&A

Reality

XML versus databases

“The truth of the matter. The RDBMS is not going anywhere anytime soon, if ever.

Even ignoring serious issues such as relational data representation in XML, the

DBMS technology is a core part of too many applications in use today. Although XML may be a realistic possibility for some smaller applications without legacy data or

legacy application dependencies, most large-scale production applications must interface with existing data. This data is almost always maintained in a relational

database.”JAVA and XML (Page 339)

By Brett McLaughlin – O’REILLY®

How Can I Access Data Using XML?

Not an easy answer! JDBC/ODBC/ADO/OLE DB XQL Xquery Xpath HTTP extensions DBMS extensions XML-QL SQL extensions …

DB Standard APIs

ODBC SQLExecDirect (hstmt, “Select * from Inventory”, SQL_NTS) SQLSetStmtAttr (hstmt, SQL_PERSIST_AS_XML, “//myweb/

inventorylist/inventory.xml”, SQL_NTS)

ADO rsXML.Open “Select * from Inventory”, conn rsXML.Save “//myweb/inventorylist/inventory.xml”,

adPersistXML

JDBC … similar using Webrowset interface

DBMS extentions

SQL Server Specify SQL Queries into the URL

http://IISServer/nwind?sql=SELECT+*+FROM+Inventory+FOR+XML+AUTO&root=root

Returns query as XML document Specify SQL Query Templates in the URL

http://IISServer/nwind/QueryFile.xml

DBMS extentions

Oracle XSQL Pages - XML formatted servlet definition that

creates or consumes XML based on the underlying databasehttp://MyServer/InventoryToday.xsql?id=12

Where XSQL defined as:<xsql:query connection=“Inventorydb" xmlns:xsql="urn:oracle-xsql">SELECT * FROM Inventory WHERE ID = '{@id}‘</xsql:query>

DBMS extentions

IBM IBM DB2 UDB (7.1) - XML Extender DAD or Document Access Definition file Flexible query or table.column based mapping Stored procedure programming model (Java,C++,...) Both retrieve and update functionality XML results are ‘dumped’ in a special DB2 table

XQuery

Example:

Return a "flat" list of supplier names and their part descriptions, in alphabetic order.

FOR $sp IN document("sp.xml")//sp_tuple, $p IN document("p.xml")//p_tuple[pno = $sp/pno], $s IN document("s.xml")//s_tuple[sno = $sp/sno] RETURN <sp_pair> $s/sname , $p/descrip </sp_pair>SORTBY (sname, descrip)

jXTransformer Introduction

Defines grammar to retrieve data and transform this into complex XML structures.

jXTransformer API that processes the Query, returns the data in the required XML structure.

jXTransformer Builder GUI tool to help you build and test queries.

Uses a DataDirect JDBC J2EE certified drivers to communicate with the RDBMS.

jXTransformer Querywith JDBC application scenario

JAVA Application with jXTransformer

Query

DataDirectJDBC Driver

RDBMS

jXTranformerAPI

XMLDocument

jXTransformer Builder

Create and modify quickly without having to know the syntax.

Check and test syntax and semantics.

jXTransformer Query Example

SELECT e.EmployeeID, e.FirstName, e.LastName, e.Title, e.HireDate, e.Salary

FROM Employees e WHERE e.HireDate = {d ’2000-01-01’}

SELECTxml_element(’Employees_Info’

xml_attribute(’ID’, e.EmployeeID),xml_element(’name’,

xml_element(’first’,e.FirstName),xml_element(’last’, e.LastName) ),

xml_element(’title’, e.Title),xml_element(’hiredate’,e.HireDate),xml_element(’salary’, e.Salary) )

FROM Employees e WHERE e.HireDate = {d ’2000-01-01’}

jXTransformer Query Example

<?xml version="1.0" encoding="UTF-8" ?><xes-result>

<Employees_Info ID='234567'><name>

<first>Jane</first><last>Smith</last>

</name><title>Director</title><hiredate>2000-01-01</hiredate><salary>120000</salary>

</Employees_Info></xes-result>

jXTransformer Query Example

jXTransformer Features

Any relational DB supported by the DataDirect JDBC drivers.

DOM, JDOM, SAX and reader/writer object interfaces.

DTDs, schemas, namespaces and CDATA. Nested jXTransformer queries. Document-level processing instructions. Parameter markers, SQL92 select list

expressions and JDBC scalar functions.

                               

jXTransformer Key Advantages

Uniform and database independent Fraction of the usual required resources Leverage existing knowledge Portable code, portable data

Q&AjXTransformer allows you to retrieve data from relational databases and transform that

data into complex XML structures .

All that is required is a JDBC connection with a DataDirect JDBC driver.

jXTransformer is flexible and powerful, allowing you to structure the data any way you want it in the resulting XML document and create well-formed and valid XML

documents for data exchange.

The jXTransformer Builder tool makes it easy for you to build and test

jXTransformer queries.

Dimitri.Maesfranckx@MERANT.COM