Error initializing descriptor

Question

Any idea why this kind of error would occur? It happens only when I create a one-one mapping between Transcation and Attachment. If I remove the mapping it works fine.
Thanks,
Rajiv
EXCEPTION [TOPLINK-0] (TopLink - 9.0.3 (Build 423)): oracle.toplink.exceptions.IntegrityException
DESCRIPTOR EXCEPTIONS:
EXCEPTION [TOPLINK-93] (TopLink - 9.0.3 (Build 423)): oracle.toplink.exceptions.DescriptorException
EXCEPTION DESCRIPTION: The table [TRX_ATTACHMENT] is not present in this descriptor.
DESCRIPTOR: Descriptor(gov.usdoj.ojp.gms.toplink.jdo.transaction.Transaction --> [DatabaseTable(TRX_TRANSACTION)])
EXCEPTION [TOPLINK-41] (TopLink - 9.0.3 (Build 423)): oracle.toplink.exceptions.DescriptorException
EXCEPTION DESCRIPTION: A non-read-only mapping must be defined for the sequence number field.
DESCRIPTOR: Descriptor(gov.usdoj.ojp.gms.toplink.jdo.transaction.Transaction --> [DatabaseTable(TRX_TRANSACTION)])

Answer 1

Darren,
Below are the descriptors generated by Toplink for the Transaction and Attachment descriptors. At the bottom of the method for buildAttachmentDescriptor there is a One to One mapping. If I remove that mapping the descriptors initialize fine. I'm not sure how adding the mapping makes the sequence field read only.
<pre>
public Descriptor buildAttachmentDescriptor() {
     Descriptor descriptor = new Descriptor();
     descriptor.setJavaClass(gov.usdoj.ojp.gms.toplink.jdo.transaction.Attachment.class);
     descriptor.addTableName("TRX_ATTACHMENT");
     descriptor.addPrimaryKeyFieldName("TRX_ATTACHMENT.TRX_ATTACHMENT_ID");
     // Descriptor properties.
     descriptor.useSoftCacheWeakIdentityMap();
     descriptor.setIdentityMapSize(100);
     descriptor.useRemoteSoftCacheWeakIdentityMap();
     descriptor.setRemoteIdentityMapSize(100);
     descriptor.setSequenceNumberFieldName("TRX_ATTACHMENT.TRX_ATTACHMENT_ID");
     descriptor.setSequenceNumberName("TRX_ATTACHMENT_SEQ");
     descriptor.setAlias("Attachment");
     // Query manager.
     descriptor.getQueryManager().checkCacheForDoesExist();
     //Named Queries
     // Event manager.
     // Mappings.
     DirectToFieldMapping idMapping = new DirectToFieldMapping();
     idMapping.setAttributeName("id");
     idMapping.setFieldName("TRX_ATTACHMENT.TRX_ATTACHMENT_ID");
     descriptor.addMapping(idMapping);
     DirectToFieldMapping nameMapping = new DirectToFieldMapping();
     nameMapping.setAttributeName("name");
     nameMapping.setFieldName("TRX_ATTACHMENT.FILE_NAME");
     descriptor.addMapping(nameMapping);
//!!!!!!!!PROBLEM MAPPING!!!!!!!//     
     OneToOneMapping blobMapping = new OneToOneMapping();
     blobMapping.setAttributeName("blob");
     blobMapping.setReferenceClass(gov.usdoj.ojp.gms.toplink.jdo.transaction.BlobData.class);
     blobMapping.useBasicIndirection();
     blobMapping.addForeignKeyFieldName("TRX_BLOB.TRX_ATTACHMENT_ID", "TRX_ATTACHMENT.TRX_ATTACHMENT_ID");
     descriptor.addMapping(blobMapping);
     return descriptor;
public Descriptor buildBlobDataDescriptor() {
     Descriptor descriptor = new Descriptor();
     descriptor.setJavaClass(gov.usdoj.ojp.gms.toplink.jdo.transaction.BlobData.class);
     descriptor.addTableName("TRX_BLOB");
     descriptor.addPrimaryKeyFieldName("TRX_BLOB.TRX_BLOB_ID");
     // Descriptor properties.
     descriptor.useSoftCacheWeakIdentityMap();
     descriptor.setIdentityMapSize(100);
     descriptor.useRemoteSoftCacheWeakIdentityMap();
     descriptor.setRemoteIdentityMapSize(100);
     descriptor.setSequenceNumberFieldName("TRX_BLOB.TRX_BLOB_ID");
     descriptor.setSequenceNumberName("TRX_BLOB_SEQ");
     descriptor.setAlias("BlobData");
     // Query manager.
     descriptor.getQueryManager().checkCacheForDoesExist();
     //Named Queries
     // Event manager.
     // Mappings.
     DirectToFieldMapping dataMapping = new DirectToFieldMapping();
     dataMapping.setAttributeName("data");
     dataMapping.setFieldName("TRX_BLOB.BLOB_INFO");
     descriptor.addMapping(dataMapping);
     DirectToFieldMapping idMapping = new DirectToFieldMapping();
     idMapping.setAttributeName("id");
     idMapping.setFieldName("TRX_BLOB.TRX_BLOB_ID");
     descriptor.addMapping(idMapping);
     return descriptor;
</pre>
Hello,
I'm guessing that by looking at the error message that the sequence number field is not writable. Also, ensure that the TRX_ATTACHMENT table is in the database.
Darren