Annotations: 3.1beta 6
Hibernate 3.1rc2
JDK 1.5.05
MYSQL 4.x

@Entity(access = AccessType.PROPERTY)
class Employee
{
@OneToMany
@JoinColumn(name="employeeOid")
public Set<EmployerEmployee> getEmployerEmployees();
}

@Entity(access = AccessType.PROPERTY)
@Table(name="EmployerEmployee"
class EmployerEmployee
{
@ManyToOne
@JoinColumn(name="employeeOid", insertable=false, updatable=false)
public Employee getEmployee()
}

So, what's the strange deal with the table name in the exception? Is that a bug?

java.sql.SQLException: Table 'MySchema.Employee_EmployerEmployees' doesn't exist
at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:2921)
at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:1570)
at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:1665)
at com.mysql.jdbc.Connection.execSQL(Connection.java:2978)
at com.mysql.jdbc.Connection.execSQL(Connection.java:2902)
at com.mysql.jdbc.PreparedStatement.executeInternal(PreparedStatement.java:930)
at com.mysql.jdbc.PreparedStatement.executeQuery(PreparedStatement.java:1024)
at com.mchange.v2.c3p0.impl.NewProxyPreparedStatement.executeQuery(NewProxyPreparedStatement.java:76)
at org.hibernate.jdbc.AbstractBatcher.getResultSet(AbstractBatcher.java:137)
at org.hibernate.loader.Loader.getResultSet(Loader.java:1676)
at org.hibernate.loader.Loader.doQuery(Loader.java:662)
at org.hibernate.loader.Loader.doQueryAndInitializeNonLazyCollections(Loader.java:223)
at org.hibernate.loader.Loader.loadCollection(Loader.java:1916)
at org.hibernate.loader.collection.CollectionLoader.initialize(CollectionLoader.java:71)
at org.hibernate.persister.collection.AbstractCollectionPersister.initialize(AbstractCollectionPersister.java:520)
at org.hibernate.event.def.DefaultInitializeCollectionEventListener.onInitializeCollection(DefaultInitializeCollectionEventListener.java:60)
at org.hibernate.impl.SessionImpl.initializeCollection(SessionImpl.java:1593)
at org.hibernate.collection.AbstractPersistentCollection.initialize(AbstractPersistentCollection.java:344)
at org.hibernate.collection.AbstractPersistentCollection.read(AbstractPersistentCollection.java:86)
at org.hibernate.collection.PersistentSet.hashCode(PersistentSet.java:355)
at java.util.HashMap.hash(HashMap.java:264)
at java.util.HashMap.containsKey(HashMap.java:342)
at java.util.HashSet.contains(HashSet.java:182)
at org.apache.commons.lang.builder.ReflectionToStringBuilder.isRegistered(ReflectionToStringBuilder.java:141)

Is "Employee" the name of the schema?

Nope, schema name is MySchema.

Dunno then, one for Emmanuel.

Error message actually says (note the lowercase e in _employerEmployees). My original message had a big E.

java.sql.SQLException: Table 'MySchema.Employee_employerEmployees' doesn't exist
at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:2921)
at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:1570)
at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:1665)

Please double check,
I'm 99% certain you have
hibernate.default_catalog=MySchema
hibernate.default_schema=Employee
in you config files

Other problem in a bidirectional relationship, one side has to be mappedBy

ah forget the mappedBy, I didn't see your insert/update=false

1% = I forgot to include the class EmployerEmployee in the hibernate config file :)

mappedBy is not needed because I used generic.

But I ran into what must be regular hibernate usage problem:

So first I used one session to query the object and at a later point used another session to delete. I think I can work this one out, but it is a bit surprising nevertheless.

org.hibernate.HibernateException: Illegal attempt to associate a collection with two open sessions
at org.hibernate.collection.AbstractPersistentCollection.setCurrentSession(AbstractPersistentCollection.java:410)
at org.hibernate.event.def.OnUpdateVisitor.processCollection(OnUpdateVisitor.java:40)
at org.hibernate.event.def.AbstractVisitor.processValue(AbstractVisitor.java:101)
at org.hibernate.event.def.AbstractVisitor.processValue(AbstractVisitor.java:61)
at org.hibernate.event.def.AbstractVisitor.processEntityPropertyValues(AbstractVisitor.java:55)
at org.hibernate.event.def.AbstractVisitor.process(AbstractVisitor.java:123)
at org.hibernate.event.def.DefaultDeleteEventListener.onDelete(DefaultDeleteEventListener.java:72)
at org.hibernate.impl.SessionImpl.fireDelete(SessionImpl.java:711)
at org.hibernate.impl.SessionImpl.delete(SessionImpl.java:691)

ah interesting. In a short future, this error won't happen anymore, we'll enforce by annotation the idea of collection of elements.

For the second, this is a common user issue, you have to close the first session before working with the objects on another one