"An Introduction to Service Data Objects"
Vol. 9, Issue 10, p. 16

	



Listing 1

//Create the basic schema description
//This describes the physical database table
//used to populate the datagraph
MetadataFactory mFactory = MetadataFactory.eINSTANCE.
Metadata metadata = mFactory.createMetadata();
	Table custTable = metadata.addTable("CUSTOMER");
	//The generated SQL SELECT will start from the single specified
	//root table
	custTable.beRoot();
	Column custID = custTable.addIntegerColumn("CUSTOMERID");
	custID.setNullable(false);
	custTable.addStringColumn("CUSTFIRSTNAME");
	custTable.addStringColumn("CUSTLASTNAME");
	custTable.setPrimaryKey(custID);

	//Add a "lastname" filter to the Customer table descriptor
	Filter filter = mFactory.createFilter();
	filter.setPredicate("CUSTOMER.CUSTLASTNAME = ?");
	FilterArgument arg = mFactory.createFilterArgument();
	arg.setName("CUSTLASTNAME");
	arg.setType(Column.STRING);
	filter.getFilterArguments().add(arg);
	custTable.setFilter(filter);

Listing 2

	//Prior to this point, the application must have
// acquired a JDBC connection for the mediator to use
	...

//Wrap the connection. The wrapper indicates whether or not the //DMS will actively
 manage the transaction. The default factory
 //method produces an "active" wrapper. Another method is //provided to create a
  "passive" wrapper which allows
//participation in a larger transaction scope
	ConnectionWrapperFactory factory =
		ConnectionWrapperFactory.soleInstance;
wrapper = factory.createConnectionWrapper(connection);

JDBCMediatorFactory fact = MediatorFactoryImpl.soleInstance;
	JDBCMediator mediator = fact.createMediator(metadata, wrapper);

Listing 3
<?xml version="1.0" encoding="ASCII"?>
<com.ibm.websphere.sdo.mediator.jdbc.metadata:Metadata xmi:version="2.0"
 xmlns:xmi="http://www.omg.org/XMI" xmlns:com.ibm.websphere.sdo.mediator.jdbc.metadata=
"http:///com/ibm/websphere/sdo/mediator/jdbc/metadata.ecore"
 rootTable="//@tables.0">
  <tables name="CUSTOMER">
    <primaryKey columns="//@tables.0/@columns.0"/>
    <columns name="CUSTOMERID"/>
    <columns name="CUSTFIRSTNAME" type="4" nullable="true"/>
    <columns name="CUSTLASTNAME" type="4" nullable="true"/>
    <filter predicate="CUSTOMER.CUSTLASTNAME = ?">
      <filterArguments name="CUSTLASTNAME" type="4"/>
    </filter>
  </tables>
</com.ibm.websphere.sdo.mediator.jdbc.metadata:Metadata>

Listing 4

//Prior to this point, the application must have
// acquired a JDBC connection for the Mediator to use
	...

//Wrap the connection
	ConnectionWrapperFactory factory =
		ConnectionWrapperFactory.soleInstance;
wrapper = factory.createConnectionWrapper(connection);

InputStream stream = new FileInputStream("myMetadata.xmi");
JDBCMediatorFactory fact = MediatorFactoryImpl.soleInstance;
JDBCMediator mediator = fact.createMediator(stream, wrapper);

Listing 5

CountingPager pager =
PagerFactory.soleInstance.createCountingPager(5);

int count = pager.pageCount(mediator);
for (int pageNum = 1, pageNum <= count, pageNum++) {

DataObject graph = pager.page(pageNum, mediator);

//Iterate through all returned customers in this page
Iterator i = graph.getList("CUSTOMER").iterator();
	while (i.hasNext()) {
	DataObject cust = (DataObject) i.next();
	System.out.println(cust.getString("CUSTFIRSTNAME"));
	}

}