Armin, thanks for your reply. But one more thing. I use table with something like 100 000 records. Using of PB.getCollectionByQuery may couse problems with memory. Out Of Memory Exception for example. This is not a problem - I can increase heap size for JVM, etc.In this case using PB.getIteratorByQuery sounds logic, I think. How I can use multiply repository profiles and still use PB.getIteratorByQuery ? I thik it will be coll when I can dynamically change only table name and operate with same object but in different db. Mapping for particular object I have alredy, one thing I need to be changed at runtime is table name. Is it possible in fact to work with big data sets in few RDBMSs ? Anyone have such expirience ? Thank you.
On Mon, 11 Apr 2005 11:40:16 +0200, Armin Waibel <[EMAIL PROTECTED]> wrote: > Hi, > > Stas Ostapenko wrote: > > I have a problem with inserting all table data of one table to another > > table in other RDBMS. Following code works, but it stores not all the > > data, but only first object. > > Where I`m wrong ? > > First you have to take care that metadata changes are global operations, > all metadata are shared. > http://db.apache.org/ojb/docu/guides/metadata.html#Global%0A++++++++++++++++++++ > > If you change the table name of a class-descriptor all other PB/threads > will use the changed table name. > > In a single threaded application you can change metadata in the > following way: > > - Lookup the PB of the source DB > - get the objects you want to copy, use PB.getCollectionByQuery instead > of PB.getIteratorByQuery (to guarantee that the objects be materialized > before the metadata change, avoid lazy materialization settings in > metadata) > - close the PB > - change the table name > - Lookup PB for target DB > - begin PB-tx > - loop and copy > - PB-tx commit > > A more elegant and multithreaded safe solution will be the usage of > different metadata profiles. You have a "normal" repository file with > all class-descriptor (with source table names) and an additionally > "profile" repository file with all class-descriptor using the target DB > table names. This profile is read at runtime (e.g. at start of your > application) and you are using the MetadataManager to setup a "source" > and a "target" metadata-profile. More detailed info here > > http://db.apache.org/ojb/docu/guides/metadata.html#Per+thread+metadata+changes > > regards, > Armin > > > > Please help. > > > > import org.apache.ojb.broker.PersistenceBroker; > > import org.apache.ojb.broker.PersistenceBrokerException; > > import org.apache.ojb.broker.PersistenceBrokerFactory; > > import org.apache.ojb.broker.query.QueryByCriteria; > > import org.apache.ojb.broker.query.Criteria; > > import org.apache.ojb.broker.metadata.DescriptorRepository; > > import org.apache.ojb.broker.metadata.FieldDescriptor; > > import org.apache.ojb.broker.metadata.MetadataManager; > > import org.apache.ojb.broker.metadata.ClassDescriptor; > > > > import java.util.Iterator; > > > > public class From_MySQL_2_HSQL_DB_testing > > { > > public static void main(String args[]) > > { > > PersistenceBroker hsql_db_broker = null; > > > > PersistenceBroker mysql_db_broker = null; > > > > Object result = null; > > > > ClassDescriptor hsql_db_Domain_classDescriptor = null; > > ClassDescriptor mysql_db_Domain_classDescriptor = null; > > try > > { > > hsql_db_broker = > > PersistenceBrokerFactory.createPersistenceBroker("HSQL_OJB_Files", > > "root", ""); > > > > mysql_db_broker = > > PersistenceBrokerFactory.createPersistenceBroker("MySQL_Main_Database", > > "root", ""); > > > > hsql_db_Domain_classDescriptor = > > hsql_db_broker.getClassDescriptor(Domain.class); > > hsql_db_Domain_classDescriptor.setTableName("hsqldb_domain"); > > > > mysql_db_Domain_classDescriptor = > > mysql_db_broker.getClassDescriptor(Domain.class); > > mysql_db_Domain_classDescriptor.setTableName("domain"); > > > > Criteria criteria = new Criteria(); > > > > criteria.addLike("Domain", "%"); > > QueryByCriteria query = new QueryByCriteria(Domain.class, > criteria); > > > > Iterator bdIterator = mysql_db_broker.getIteratorByQuery(query); > > > > while(bdIterator.hasNext()) > > { > > mysql_db_Domain_classDescriptor.setTableName("domain"); > > result = bdIterator.next(); > > > > hsql_db_Domain_classDescriptor.setTableName("hsqldb_domain"); > > hsql_db_broker.beginTransaction(); > > hsql_db_broker.store(result); > > hsql_db_broker.commitTransaction(); > > System.out.println(((Domain)result).Name); > > } > > } > > catch(Exception e) > > { > > e.printStackTrace(); > > } > > finally > > { > > //close HSQLDB connection > > hsql_db_broker.close(); > > > > //close MySQL connection > > mysql_db_broker.close(); > > } > > } > > } > > > > --------------------------------------------------------------------- > > To unsubscribe, e-mail: [EMAIL PROTECTED] > > For additional commands, e-mail: [EMAIL PROTECTED] > > > > > > > > > --------------------------------------------------------------------- > To unsubscribe, e-mail: [EMAIL PROTECTED] > For additional commands, e-mail: [EMAIL PROTECTED] > > --------------------------------------------------------------------- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
