Use the Enterprise JavaBeans data mediator service for data access

The following steps use code samples to describe a simple instance of how to create the Enterprise JavaBeans data mediator service (DMS) metadata.

Procedure

1. A mediator instance is created using one of the create methods on the mediator factory (com.ibm.websphere.sdo.mediator.ejb.MediatorFactory) as in the following example

   import com.ibm.websphere.sdo.mediator.ejb.Mediator;
   import com.ibm.websphere.sdo.mediator.ejb.MediatorFactory;
   import com.ibm.webpshere.ejbquery.QueryException;
   import commonj.sdo.DataObject;
   
   try{
    String[] query =  { "select d.deptno,d.name from DeptBean as d" }; 
    Mediator m = MediatorFactory.getInstance().createMediator( query, null);
    DataObject root = m.getGraph();
   } catch (QueryException e) { ... } 

2. There are 3 different forms of the createMediator method. The arguments are explained below.

   createMediator( query, parms) 
   createMediator( query, parms, schema )
   createMediator( query, parms, schema,  typeMap,  pattern)

   The arguments to the createMediator method are:

   String	query	array of EJB query statements
   Object	parms	values for input parameters of the query statements
   Eclass*	schema	the EClass of the root DataObject
   Map*	typeMap	a java.util.Map that maps EJB Abstract Schema Names from the query statement into Eclass names
   int*	pattern	the pattern used for containment
   * used only when using caller provided schema

Related Reference