Fully Loaded Database Driver with Hybrid Power · 2013-05-29 · Metadata type java.sql.Types.OTHER java.sql.Types.SQLXML Metadata type name Java class "XML" "XML" com.ibm.db2.jcc.DB2Xml

© 2009 IBM Corporation

Bilung Lee, Ph.D., [email protected] Silicon Valley Laboratory

Fully Loaded Database Driver with Hybrid Power


2Outline• Driver Overview• XML Data Type• XML Data Type in Java Procedures• XML Schema• SQL/XML• XQuery


3

Driver Overview


4

COM.ibm.db2.jdbc.app.DB2DriverCOM.ibm.db2.jdbc.net.DB2Driver

Legacy driver (DB2 for LUW)

COM.ibm.db2os390.sqlj.jdbc.DB2SQLJDriverLegacy driver (DB2 for zOS)

com.ibm.db2.jcc.DB2DriverIBM Data Server Driver

Driver classDriver

IBM Data Server Driver• A single driver (also known as JCC driver) enables

Java access across DB2 product family


5IBM Data Server Driver (continued)• Both JDBC and SQLJ access• Multiple platforms, including DB2 for Linux, Unix,

and Windows, DB2 for z/OS, DB2 for iSeries, Informix IDS, and Cloudscape

• Different connectivity paths (local and remote)• Type 2: Local via native attach on z/OS• Type 2: Local via shared memory on LUW• Type 4: Remote via DRDA protocol (pure Java)

• Direct Access from remote (no need for gateway)


6

Type 2 Connectivityfor zOS

Common APIsfor JDBC and SQLJ

Type 4 Connectivity Type 2 Connectivityfor LUW

DRDAover

TCP/IP

Native AttachDRDA

overShared Memory

DB2 for zOS

Native Libraries

Common Architecture

DB2 for LUW

Native Libraries


7Typical Usage

DB2ConnectGateway

JCC Type 4

Applications /Application Servers

JCC Type 2

Applications /Application Servers

JCCType 2

JavaStored Procs

InformixIDS

JCCType 2

JavaStored Procs

DB2 for LUW

DB2 for z/OS


8Connectivity Selection• Considerations

• T4 connectivity is binary portable• T4 connectivity can run with a security manager• T4 connectivity equips with XA support for

distributed transactions• T2 connectivity performs better for local

connections• T2 connectivity is used by Java Stored

Procedures• Applications may switch between different

connectivity types


9

6.0JDBC 4.0 and earlier

JCC 4db2jcc4.jar*

* Available starting from DB2 for LUW version 9.5

1.4JDBC 3.0 and earlier

JCC 3db2jcc.jar

Minimum level of Java

Level of JDBC support

Driver versionJAR file

Providing Two JAR Files


10

XX**XQuery

* GA of version 9.5 is October 2007** Only XPath is supported

SQL/XML

XML schema registration

XML data type in Java procedures

XML data type

Feature

X

X

X

DB2 for zOS(March 2007 GA)

X

X

X

X

DB2 for LUW(July 2006 GA)*

XML Support on DB2 Version 9


11

XML Data Type


12

java.sql.Types.SQLXMLjava.sql.Types.OTHERMetadata type

Metadata type name

Java class

"XML""XML"

java.sql.SQLXMLcom.ibm.db2.jcc.DB2Xml

JCC 4 driver(db2jcc4.jar)

JCC 3 driver(db2jcc.jar)

Data Type• A built-in data type on DB2 since version 9• An XML data type can be accessed via string,

bytes, stream, DB2Xml, and SQLXML in JCC


13

getAsciiStreamgetStringgetCharacterStream

getBytesgetBinaryStream

getObjectgetSQLXML*

* Only supported in JCC 4 driver and above

ASCII dataUCS-2 dataUTF-8 dataAbstract data

Data Retrieval• Methods on ResultSet to retrieve data from XML

columns


14Data Retrieval (continued)• For exampleresultSet = statement.executeQuery("SELECT ORDER FROM ORDERS");

resultSet.next();byte[] xmlBytes = resultSet.getBytes(1);String xmlString = resultSet.getString(1);DB2Xml db2xml = (DB2Xml)resultSet.getObject(1);// following only applicable to the JCC 4 driver and aboveSQLXML sqlxml = resultSet.getSQLXML(1);


15

getDB2XmlAsciiStream()getDB2AsciiStream()ASCII data

getDB2Bytes()getDB2BinaryStream()

UTF-8 data

getDB2XmlString()getDB2XmlCharacterStream()

getDB2String()getDB2CharacterStream()

UCS-2 data

getDB2XmlBytes(encoding)getDB2XmlBinaryStream(encoding)

Various encoding data

With declarationWithout declaration

Data Retrieval (continued)• Methods on DB2Xml to retrieve data


16Data Retrieval (continued)• For exampleDB2Xml db2xml = (DB2Xml)resultSet.getObject(1);byte[] db2xmlBytes = db2xml.getDB2XmlBytes("EUC-JP");fileOutputStream = newjava.io.FileOutputStream("PurchaseOrder.EUC-JP.xml");

fileOutputStream.write(db2xmlBytes);fileOutputStream.flush();


17

getSource(StreamSource.class)Stream source

getString()getCharacterStream()

getBinaryStream()With serialization

getSource(SAXSource.class)SAX sourcegetSource(StAXSource.class)StAX source

UCS-2 data

getSource(DOMSource.class)DOM source

UTF-8 dataWithout serialization

Data Retrieval (continued)• Methods on SQLXML to retrieve data


18Data Retrieval (continued)• For exampleSQLXML sqlxml = resultSet.getSQLXML(1);SAXSource source = sqlxml.getSource(SAXSource.class);XMLReader reader = source.getXMLReader();ContentHandler myHandler = ...;reader.setContentHandler(myHandler);reader.parse(source.getInputSource());


19

YesYesYesReadable

YesNoYesWritable

NoNoYesTraversable

NoNoYesUpdatable

Streaming, PullStreaming, PushTreeModelStAXSAXDOM

Data Processing• Parsing, validating, and transforming• Comparison


20Data Processing (continued)• DOM (Document Object Model)

• Available since Java 1.4• A tree based API for random access to an XML

document• Most common XML API in use

• SAX (Simple API for XML)• Available since Java 1.4• A series of events generated as entities are

encountered within an XML document• Generally faster than DOM


21Data Processing (continued)• StAX (Streaming API for XML)

• Available in Java 6• Pull the information out of an XML document as

needed• Also provide ability to write an XML document

• XSLT (XML Stylesheet Transform)• Available since Java 1.4• Transform XML formats from Source to Result• Transform XML among DOM/SAX/StAX/Stream


22Data Processing (continued)• For exampleSQLXML sqlxml = resultSet.getSQLXML(1);DOMSource source = sqlxml.getSource(DOMSource.class);Result result = new StreamResult(new File("result.xml"));Source xslt = new StreamSource(new File("format.xslt"));Transformer transformer =TransformerFactory.newInstance().newTransformer(xslt);

transformer.transform(source, result);


23

setStringsetAsciiStreamsetCharacterStreamsetObject(String)

setBytessetBinaryStreamsetSQLXML*setObject(byte[])setObject(DB2Xml)setObject(SQLXML)*

* Only supported in JCC 4 driver and above

Externally coded XML dataInternally coded XML data

Data Update• Methods on PreparedStatement to update data in

XML columns


24Data Update (continued)• For examplestatement.execute("CREATE TABLE ORDERS (ORDER

XML)");preparedStatement = connection.prepareStatement("INSERT INTO ORDERS VALUES (?)");

fileInputStream = new FileInputStream("PurchaseOrder.xml");inputStreamReader = new InputStreamReader(fileInputStream,encoding);

preparedStatement.setCharacterStream(1, inputStreamReader,

numberOfCharactersInFile);preparedStatement.execute();


25

setResult(StreamResult.class)Stream result

setString(String)setCharacterStream()

setBinaryStream()With serialization

setResult(SAXResult.class)SAX resultsetResult(StAXResult.class)StAX result

Externally coded

setResult(DOMResult.class)DOM result

Internally codedWithout serialization

Data Update (continued)• DB2Xml is immutable and cannot be changed• Methods on SQLXML to update data


26Data Update (continued)• For exampleSQLXML sqlxml = connection.createSQLXML();SAXResult result = sqlxml.setResult(SAXResult.class);ContentHandler handler =result.getXMLReader().getContentHandler();

handler.startDocument();... // write elements and attributes to the resulthandler.endDocument();


27

YESYEScreateSQLXML() of Connection

NONOsetXXX() of SQLXML

NONOgetXXX() of SQLXML

WritableReadableMethod called

SQLXML Data• An SQLXML may or may not be readable/writable

after a corresponding method is called


28

XML Data Type inJava Procedures


29Stored Procedures• On DB2 for zOS, stored procedure parameters

currently cannot have any XML data type• On DB2 for LUW

• For SQL procedures, XML parameters can have the XML type

• For external procedures, XML parameters can have the XML AS CLOB type

• Need to use a compatible data type in the invoking statement


30Java Procedures• As mentioned, only on DB2 for LUW so far• JCC driver is required for necessary XML support• The corresponding type in Java is DB2Xml• Starting from version 9.5, JCC driver becomes the

default driver• In earlier versions, legacy type 2 driver is still used

by default• To make sure that JCC driver is used

db2set DB2_USE_DB2JCCT2_JROUTINE=YES


31Stored Procedure Creation• In SQL, XML parameters are declared as XML AS

CLOB(n)statement.execute("CREATE PROCEDURE XMLPROC" +"(INOUT IOXML XML AS CLOB(2M)) " +"EXTERNAL NAME " +" 'XmlProcJar:XmlProcClass.xmlProcMethod' " +"LANGUAGE JAVA " +"PARAMETER STYLE JAVA");


32Stored Procedure InvocationcallableStatement = c.prepareCall("CALL XMLPROC(?)");callableStatement.registerOutParameter(1, DB2Types.XML);callableStatement.execute();DB2Xml db2xml = (DB2Xml)callableStatement.getObject(1);


33Stored Procedure Content• In Java, XML parameters are declared as DB2Xmlpublic class XmlProcClass {public static void xmlProcMethod(DB2Xml[] ioXml) {Connection connection =DriverManager.getConnection("jdbc:default:connection");

...resultSet = statement.executeQuery(...);ioXml[0] = (DB2Xml)resultSet.getObject(1);

}}


34

XML Schema


35Registration• Three stored procedures are defined on DB2

• SYSPROC.XSR_REGISTER• SYSPROC.XSR_ADDSCHEMADOC• SYSPROC.XSR_COMPLETE

• Convenient methods are provided in JCC• Register multiple XML schema documents for

an XML schema within one method call• One form of method takes InputStream objects

as XML schema documents• Another of method takes String objects as XML

schema documents


36Registration (continued)• For examplejava.sql.DatabaseMetaData meta = connection.getMetaData();String sqlIdSchema[] = new String[1];if (meta.getDatabaseProductVersion().startsWith("DSN"))sqlIdSchema[0] = "SYSXSR";

else if (meta.getDatabaseProductVersion().startsWith("SQL"))sqlIdSchema[0] = "MYXSR";

String sqlIdName[] = new String[] {"ORDER"};


37Registration (continued)String[] xmlSchemaLocations = new String[] {"order.xsd", "header.xsd", "cust.xsd", "prod.xsd“

};FileInputStream[] xmlSchemaDocuments =new FileInputStream[] {new FileInputStream("schema/order.xsd"),new FileInputStream("schema/header.xsd"),new FileInputStream("schema/cust.xsd"),new FileInputStream("schema/prod.xsd")

};


38Registration (continued)int[] xmlSchemaDocumentsLengths = new int[] {(int)xmlSchemaDocuments[0].getChannel().size(),(int)xmlSchemaDocuments[1].getChannel().size(),(int)xmlSchemaDocuments[2].getChannel().size(),(int)xmlSchemaDocuments[3].getChannel().size()

};InputStream[] xmlSchemaDocumentsProperties = null;int[] xmlSchemaDocumentsPropertiesLengths = null;InputStream xmlSchemaProperties = null; int xmlSchemaPropertiesLength = 0; boolean isUsedForShredding = false;


39Registration (continued)connection.registerDB2XmlSchema(sqlIdSchema,sqlIdName,xmlSchemaLocations,xmlSchemaDocuments,xmlSchemaDocumentsLengths,xmlSchemaDocumentsProperties,xmlSchemaDocumentsPropertiesLengths,xmlSchemaProperties,xmlSchemaPropertiesLength,isUsedForShredding);


40Deregistration• A stored procedure SYSPROC.XSR_REMOVE is

defined on DB2 for zOS• A SQL statement DROP XSROBJECT is provided

instead on DB2 for LUW• A convenient method is provided in JCC

• Allow removal of an XML schema from DB2• Automatically choose between stored procedure

call or statement execution based on target DB2 platform


41Deregistration (continued)• For examplejava.sql.DatabaseMetaData meta = connection.getMetaData();String sqlIdSchema = null;if (meta.getDatabaseProductVersion().startsWith("DSN"))sqlIdSchema = "SYSXSR";

else if (meta.getDatabaseProductVersion().startsWith("SQL"))sqlIdSchema = "MYXSR";

String sqlIdName = "ORDER";connection.deregisterDB2XmlObject(sqlIdSchema,

sqlIdName);


42Update• A stored procedure SYSPROC.XSR_UPDATE is

defined on DB2 for LUW starting from version 9.5• A convenient method is provided in JCC• The content of an original XML schema can be

updated with the content of a new XML schema• Both the original and the new XML schemas must

already be registered• Only compatible updates are allowed, for example,

adding optional elements• Existing documents that are validated remain valid


43Update (continued)• For exampleString originalSchema = "XSR1";String originalName = "NAME1";String newSchema = "XSR2";String newName = "NAME2";connection.updateDB2XmlSchema(originalSchema,

originalName,newSchema, newName, true);


44Validation• Validation function

• On DB2 for zOS• Use DSN_XMLVALIDATE• The schema is SYSFUN

• On DB2 for LUW• Use XMLVALIDATE• The schema is SYSIBM• Cannot be specified as a qualified name

• For examplejava.sql.DatabaseMetaData meta = connection.getMetaData();


45Validation (continued)if (meta.getDatabaseProductVersion().startsWith("DSN"))sql ="INSERT INTO ORDERS VALUES (XMLPARSE(DOCUMENT " +"DSN_XMLVALIDATE" +"(CAST(? AS BLOB(1G)), 'SYSXSR.ORDER')" +"))";

else if (meta.getDatabaseProductVersion().startsWith("SQL"))sql = "INSERT INTO ORDERS VALUES (" +"XMLVALIDATE" +"(? ACCORDING TO XMLSCHEMA ID MYXSR.ORDER)" +")";


46Validation (continued)preparedStatement = connection.prepareStatement(sql);fileInputStream = new FileInputStream("PurchaseOrder.xml");preparedStatement.setBinaryStream(1, fileInputStream,(int)fileInputStream.getChannel().size());

preparedStatement.execute();


47

SQL/XML


48SQL/XML• Enable support for using XML in the context of an

SQL database system• XML extensions of SQL

• XML publishing functions• XML data type• Mapping rules


49

XMLAGGAggregate function

XMLATTRIBUTESXMLCOMMENTXMLCONCATXMLDOCUMENTXMLELEMENTXMLFORESTXMLPIXMLTEXT

Scalar function

XMLNAMESPACESDeclaration functionFunctionsType

Publishing Functions


50Publishing Functions (continued)• For exampleresultSet = statement.executeQuery("SELECT XMLELEMENT (" +" NAME \"employee\"," +" XMLNAMESPACES (DEFAULT

'http://www.ibm.com')," +" XMLATTRIBUTES (E.ID, E.FULLNAME AS

\"name\")," +" XMLFOREST ("+" E.ADDRESS AS \"address\", E.CITY AS \"city\"," +" E.STATE AS \"state\", E.ZIPCODE AS \"zip\"" +" )" +") FROM EMPLOYEE AS E");


51Publishing Functions (continued)• Each row of the result set is an employee element<employee xmlns="http://www.ibm.com" ID="1001"

name="Jane Doe"><address>555 Bailey Ave</address><city>San Jose</city><state>California</state><zip>95141</zip></employee>

<employee xmlns="http://www.ibm.com" ID="1002" name="John Doe"><address>8200 Warden Ave</address><city>Markham</city><state>Ontario</state><zip>L6G1C7</zip></employee>


52

xs:floatREAL

xs:longBIGINT

xs:decimalDECIMAL, NUMERIC

xs:intINTEGER

xs:doubleFLOAT, DOUBLE

xs:shortSMALLINT

xs:stringCHAR, VARCHAR

XML schema data typesSQL data types

Mapping Rules• Mapping between SQL data types and XML

schema data types


53

XQuery


54XQuery• The language for querying and modifying XML

data• Designed for XML data just as SQL designed for

relational data• Case-sensitive and all keywords in lower-case• Built on top of XPath• Compatible with several W3C standards

• XML• XML Schema• Namespaces• XSLT


55Direct Invocation• XQuery is supported as first-class language• Not required to wrap XQuery inside SQL• Can exploit XQuery individually• Prefaced with the keyword XQUERY• Only available on DB2 for LUW so far


56Hybrid Power• DB2 is equipped with both XQuery and SQL

language parsers• Both languages are compiled into the same

intermediate query representation• Can leverage “bilingual” queries• Deeper levels of nesting is also allowed• Choose the right model for the right task


57Hybrid Power (continued)• Embed SQL in XQuery

• Only available on DB2 for LUW so far• Embed columns

db2-fn:xmlcolumn('SCHEMA.TABLE.COLUMN')• Embed query

db2-fn:sqlquery('select column from schema.table')• Embed XQuery in SQL

• Available on DB2 for both LUW and zOS• Use XMLQUERY SQL scalar function• Only XPath is supported on DB2 for zOS


58SQL in XQueryresultSet = statement.executeQuery("XQUERY " +"declare default element namespace" +" \"http://jcc/account\";" +"<maillist>{" +"for $c in" +" db2-fn:sqlquery(\"SELECT OWNER FROM

ACCOUNT\")" +"where $c/owner[country=\"USA\"]" +"return" +" <customer>{$c//name} {$c//address}</customer>" +"}</maillist>"

);


59XQuery in SQLresultSet = statement.executeQuery("SELECT XMLQUERY ('" +" declare default element namespace" +" \"http://jcc/account\";" +" $customer/owner[country=\"USA\"]" +"' PASSING OWNER AS \"customer\"" +") FROM ACCOUNT"

);


60XQuery in SQL (Host Variables)preparedStatement = c.prepareStatement("SELECT XMLQUERY ('" +" declare default element namespace" +" \"http://jcc/account\";" +" $customer/owner[country=$nation] " +"' PASSING OWNER AS \"customer\"," +" CAST (? AS VARCHAR(20)) AS \"nation\"" +") FROM ACCOUNT"

);preparedStatement.setString(1, "USA");resultSet = preparedStatement.executeQuery();


61Summary• Learn about IBM Data Server Driver for JDBC and

SQLJ• Learn the rich selection of interfaces for accessing

XML• Learn the XML schema registration• Learn the emerging SQL/XML feature• Learn the emerging XQuery feature• Learn to leverage the hybrid power


62Questions/Comments