Exception is thrown when closing the SessionFactory using c3p0 and hibernate.hbm2ddl.auto set to "create-drop".

Hibernate version: 3.2.2

Hibernate annotation version: 3.2.1

Full stack trace of any exception that occurs:
INFO Feb 07 2007 03:49:45 org.hibernate.impl.SessionFactoryImpl - closing
INFO Feb 07 2007 03:49:45 org.hibernate.tool.hbm2ddl.SchemaExport - Running hbm2ddl schema export
DEBUG Feb 07 2007 03:49:45 org.hibernate.tool.hbm2ddl.SchemaExport - import file not found: /import.sql
INFO Feb 07 2007 03:49:45 org.hibernate.tool.hbm2ddl.SchemaExport - exporting generated schema to database
ERROR Feb 07 2007 03:49:45 org.hibernate.tool.hbm2ddl.SchemaExport - schema export unsuccessful
java.sql.SQLException: com.mchange.v2.c3p0.PoolBackedDataSource@24a8e5c0 [ connectionPoolDataSource -> com.mchange.v2.c3p0.WrapperConnectionPoolDataSource@c903c053 [ acquireIncrement -> 1, acquireRetryAttempts -> 30, acquireRetryDelay -> 1000, autoCommitOnClose -> false, automaticTestTable -> null, breakAfterAcquireFailure -> false, checkoutTimeout -> 0, connectionCustomizerClassName -> null, connectionTesterClassName -> com.mchange.v2.c3p0.impl.DefaultConnectionTester, debugUnreturnedConnectionStackTraces -> false, factoryClassLocation -> null, forceIgnoreUnresolvedTransactions -> false, identityToken -> 1hge1397k16tgk661tcbuh5|146b6db, idleConnectionTestPeriod -> 300, initialPoolSize -> 10, maxAdministrativeTaskTime -> 0, maxConnectionAge -> 0, maxIdleTime -> 100, maxIdleTimeExcessConnections -> 0, maxPoolSize -> 100, maxStatements -> 0, maxStatementsPerConnection -> 0, minPoolSize -> 10, nestedDataSource -> com.mchange.v2.c3p0.DriverManagerDataSource@da490ca9 [ description -> null, driverClass -> null, factoryClassLocation -> null, identityToken -> 1hge1397k16tgk661tcbuh5|c792d4, jdbcUrl -> jdbc:mysql://localhost/transpacifictest, properties -> {user=******, password=******, autocommit=false} ], preferredTestQuery -> null, propertyCycle -> 0, testConnectionOnCheckin -> false, testConnectionOnCheckout -> false, unreturnedConnectionTimeout -> 0, usesTraditionalReflectiveProxies -> false; userOverrides: {} ], dataSourceName -> null, factoryClassLocation -> null, identityToken -> 1hge1397k16tgk661tcbuh5|6c5482, numHelperThreads -> 3 ] has been closed() -- you can no longer use it.
at com.mchange.v2.c3p0.impl.AbstractPoolBackedDataSource.assertCpds(AbstractPoolBackedDataSource.java:447)
at com.mchange.v2.c3p0.impl.AbstractPoolBackedDataSource.getPoolManager(AbstractPoolBackedDataSource.java:459)
at com.mchange.v2.c3p0.impl.AbstractPoolBackedDataSource.getConnection(AbstractPoolBackedDataSource.java:128)
at org.hibernate.connection.C3P0ConnectionProvider.getConnection(C3P0ConnectionProvider.java:56)
at org.hibernate.tool.hbm2ddl.SuppliedConnectionProviderConnectionHelper.prepare(SuppliedConnectionProviderConnectionHelper.java:27)
at org.hibernate.tool.hbm2ddl.SchemaExport.execute(SchemaExport.java:180)
at org.hibernate.tool.hbm2ddl.SchemaExport.drop(SchemaExport.java:143)
at org.hibernate.impl.SessionFactoryImpl.close(SessionFactoryImpl.java:810)
....

Name and version of the database you are using: MySQL 4.1.22


Debug level Hibernate log excerpt: DEBUG, INFO

Hai

After seeing your log, I am guessing that the error is in the hibernat.hb2dll.auto which is throwing an exception so try to comment that line in hibernate.cfg.xml and run once and see.Actually i never tried with c3po .


Please let me know whether it has helped you or not.

When hibernate.hbm2ddl.auto is set to "create", "update" or "verify", it will not throw exception when closing the SessionFactory.

Only when set to "create-drop" it will generate the exception.

Also when c3p0 is disabled, there will be no exception

This looks like a recrudescence of an old (resolved) issue, whereby schema update code close()ed ConnectionProviders out from under applications. [ See http://forum.hibernate.org/viewtopic.php?t=955212 ] In your case, you're already in SessionFactory.close(), so close()ing the ConnectionProvider associated with that factory seems reasonable, but it looks like the ConnectionProvider is close()ed prior to the table drop when create-drop is set.

This sort of error might not show up with unpooled ConnectionProviders, because destroying an unpooled ConnectionProvider can be implemented as a no-op. But with a c3p0-based ConnectionProvider, close() is not a no-op; it invalidates the internal c3p0 DataSource. So if the ConnectionProvider is close()ed prior to the attempt to drop schema, it may work in the unpooled case, but fail with c3p0.

This is just a guess, though. I haven't checked hibernate source to verify.

Good luck!