Hello all,

I am studing Hibernate to use it with a new project (DB is Postgresql 7.4

), but got the following problem:

net.sf.hibernate.JDBCException: Could not save object
at net.sf.hibernate.impl.SessionImpl.saveWithGeneratedIdentifier(SessionImpl.java:744)
at net.sf.hibernate.impl.SessionImpl.save(SessionImpl.java:717)
at ConexaoHibernate.inserirEntidade(ConexaoHibernate.java:36)
at Principal.main(Principal.java:29)
Caused by: org.postgresql.util.PSQLException: ERROR: relation "hibernate_sequence" does not exist

at org.postgresql.util.PSQLException.parseServerError(PSQLException.java:139)
at org.postgresql.core.QueryExecutor.executeV3(QueryExecutor.java:154)
at org.postgresql.core.QueryExecutor.execute(QueryExecutor.java:101)
at org.postgresql.core.QueryExecutor.execute(QueryExecutor.java:43)
at org.postgresql.jdbc1.AbstractJdbc1Statement.execute(AbstractJdbc1Statement.java:515)
at org.postgresql.jdbc2.AbstractJdbc2Statement.execute(AbstractJdbc2Statement.java:50)
at org.postgresql.jdbc1.AbstractJdbc1Statement.executeQuery(AbstractJdbc1Statement.java:231)
at net.sf.hibernate.id.SequenceGenerator.generate(SequenceGenerator.java:69)
at net.sf.hibernate.impl.SessionImpl.saveWithGeneratedIdentifier(SessionImpl.java:727)
... 3 more

During the logging process everything seems to be fine until:

14080 [main] DEBUG net.sf.hibernate.impl.BatcherImpl - about to open: 0 open PreparedStatements, 0 open ResultSets
14090 [main] DEBUG net.sf.hibernate.SQL - select nextval ('hibernate_sequence')
Hibernate: select nextval ('hibernate_sequence')
14090 [main] DEBUG net.sf.hibernate.impl.BatcherImpl - preparing statement
15021 [main] DEBUG net.sf.hibernate.util.JDBCExceptionReporter - SQL Exception
org.postgresql.util.PSQLException: ERROR: relation "hibernate_sequence" does not exist

at org.postgresql.util.PSQLException.parseServerError(PSQLException.java:139)
at org.postgresql.core.QueryExecutor.executeV3(QueryExecutor.java:154)
at org.postgresql.core.QueryExecutor.execute(QueryExecutor.java:101)
at org.postgresql.core.QueryExecutor.execute(QueryExecutor.java:43)
at org.postgresql.jdbc1.AbstractJdbc1Statement.execute(AbstractJdbc1Statement.java:515)
at org.postgresql.jdbc2.AbstractJdbc2Statement.execute(AbstractJdbc2Statement.java:50)
at org.postgresql.jdbc1.AbstractJdbc1Statement.executeQuery(AbstractJdbc1Statement.java:231)
at net.sf.hibernate.id.SequenceGenerator.generate(SequenceGenerator.java:69)
at net.sf.hibernate.impl.SessionImpl.saveWithGeneratedIdentifier(SessionImpl.java:727)
at net.sf.hibernate.impl.SessionImpl.save(SessionImpl.java:717)
at ConexaoHibernate.inserirEntidade(ConexaoHibernate.java:36)
at Principal.main(Principal.java:29)
15082 [main] WARN net.sf.hibernate.util.JDBCExceptionReporter - SQL Error: 0, SQLState: 42P01
15092 [main] ERROR net.sf.hibernate.util.JDBCExceptionReporter - ERROR: relation "hibernate_sequence" does not exist

15092 [main] DEBUG net.sf.hibernate.impl.BatcherImpl - done closing: 0 open PreparedStatements, 0 open ResultSets
15092 [main] DEBUG net.sf.hibernate.impl.BatcherImpl - closing statement
15152 [main] DEBUG net.sf.hibernate.util.JDBCExceptionReporter - SQL Exception
org.postgresql.util.PSQLException: ERROR: relation "hibernate_sequence" does not exist


Can anyone help me out ??

Happy new year for everyone,

Luiz

Hibernate is trying to get the next identity value by executing select nextval ('hibernate_sequence'). I would suspect there is no sequence called hibernate_sequence in your db, and you need to define one. Don't know how this works using Postgre however

Thank you,

Already figured it out. It works using the generator as following:

<generator class="increment"/>

and

unsaved-value="-1"

as in

<id name="idCliente" column="ID_CLIENTE" type="long" unsaved-value="-1">

The Hibernate did all the rest.

Note however that using increment generator is not particulary save. You should probably try to get sequence to work, this is definately better, and should really just involve adding a sequence to your database (Postger users, speak up how to do this ;)

It's safe in a non multithreaded, non clustered environnement.