Question

For security reasons, our oracle db objects normally belong to a different schema than the logged in user. Eg. tables are in xx_core and the user we log in is xx_app_yy .
In my persistence.xml I define a orm file so that I can specify the schema name at deploy time eg.:
<mapping-file>xx_schema_orm.xml</mapping-file>

Then in the xx_schema_orm.xml I can define the object-owning-schema eg.:

<persistence-unit-metadata>
  <persistence-unit-defaults>
    <schema>xx_core</schema>
  </persistence-unit-defaults>
</persistence-unit-metadata>

This works great for tables, but I can’t find the equivalent for sequences. It tries to use the sequence without the schema name and then I get an exception:

2010-10-14 03:04:05,423:DEBUG   could not get next sequence value [select xx_SEQ.nextval from dual]     - org.hibernate.util.JDBCExceptionReporter
java.sql.SQLException: ORA-02289: sequence does not exist

    at oracle.jdbc.driver.DatabaseError.throwSqlException(DatabaseError.java:145)

I’ve tried to set the schema name as part of the sequence name for a generator in the xx_schema_orm.xml, but could not get it working eg.:

<sequence-generator name="xx_SEQ_GEN"
sequence-name="xx_core.xx_SEQ"/>

Workarounds I may try:

• make a database SYNONYM for the sequences in the user’s schema.
• stop using sequences and use some other way to generate ids.

Answer 1

In JPA 2.0:

• the @SequenceGenerator annotation and the equivalent sequence-generator element do allow to specify a schema (and catalog) name.
• the schema subelement should be honored by sequence generators as well.

But this doesn’t apply to JPA 1.0.

I’ll just quote the sections about the schema subelement to illustrate the differences (other relevant sections are mentioned in the references below). From the JPA 2.0 specification:

12.2.1.1 schema

The schema subelement applies to all entities, tables, secondary
tables, join tables, collection
tables, table generators, and
sequence generators in the persistence unit.

The schema subelement is overridden
by any schema subelement of the
entity-mappings element; any schema
element explicitly specified in the
Table or SecondaryTable annotation
on an entity or any schema attribute
on any table or secondary-table
subelement defined within an entity
element; any schema element
explicitly specified in a
TableGenerator annotation or
table-generator subelement; any
schema element explicitly specified in
a SequenceGenerator annotation or
sequence-generator subelement; any
schema element explicitly specified
in a JoinTable annotation or
join-table subelement; and any
schema element explicitly specified in
a CollectionTable annotation or
collection-table subelement.

From the JPA 1.0 specification:

10.1.1.1 schema

The schema subelement applies to all
entities, table generators, and join
tables in the persistence unit.

The schema subelement is overridden
by any schema subelement of the
entity-mappings element; any
schema element explicitly specified
in the Table or SecondaryTable
annotation on an entity or any schema
attribute on any table or
secondary-table subelement defined
within an entity element; any
schema element explicitly specified
in a TableGenerator annotation or
table-generator subelement; and any
schema element explicitly specified
in a JoinTable annotation or
join-table subelement.

So, unless your provider offers some specific extensions, my suggestions are:

• Upgrade to JPA 2.0 if possible and using the schema subelement will do the trick ~or~
• Use a TableGenerator if you have to stick with JPA 1.0 ~or~
• Use an alias if this is possible (I don’t know).

References

• JPA 1.0 Specification
  • Section 9.1.37 “SequenceGenerator Annotation”
  • Section 10.1.1.1 “schema”
  • Section 12.2.2.5 “sequence-generator”
• JPA 2.0 Specification
  • Section 11.1.44 “SequenceGenerator Annotation”
  • Section 12.2.1.1 “schema”
  • Section 12.2.2.5 “sequence-generator”