Now I stepped over to sqlQuery since criteria didn't work.
When I change "%" in to "'%'" during debug the code runs through en I get a result.
Second run the code throws an error. When I change back to "%" the code runs through again. Second run it again trows error.
Is this a bug in hibernate? or am I just running a code that that is out of reach for hibernate?

Hibernate version:
2.1.8
Mapping documents:
Look at topic JDBC Exception
Code between sessionFactory.openSession() and session.close():

Full stack trace of any exception that occurs:
[11:45:38,406] WARN JDBCExceptionReporter:57 - SQL Error: 1401, SQLState: 23000

[11:45:38,406] ERROR JDBCExceptionReporter:58 - ORA-01401: inserted value too large for column

[11:45:38,406] WARN JDBCExceptionReporter:57 - SQL Error: 1401, SQLState: 23000

[11:45:38,406] ERROR JDBCExceptionReporter:58 - ORA-01401: inserted value too large for column

[11:45:38,421] WARN JDBCExceptionReporter:57 - SQL Error: 1401, SQLState: 23000

[11:45:38,421] ERROR JDBCExceptionReporter:58 - ORA-01401: inserted value too large for column

[11:45:38,421] WARN JDBCExceptionReporter:57 - SQL Error: 1401, SQLState: 23000

[11:45:38,437] ERROR JDBCExceptionReporter:58 - ORA-01401: inserted value too large for column

[11:45:38,437] ERROR SessionImpl:2400 - Could not synchronize database state with session

Name and version of the database you are using:
Oracle 9i
The generated SQL (show_sql=true):
Hibernate: update WORKMATE set PPO_ID=?, DOMAIN_ID=?, FIRSTNAME=?, MIDDLENAME=?,
LASTNAME=?, GENDER=?, DATE_OF_BIRTH=?, ZIPCODE_HOME=?, ZIPCODE_WORK=?, EDUCATIO
N=?, MARITAL_STATUS=?, IS_ACCEPTED=?, HAS_PROFILE=?, IS_ACTIVE=?, PROFILE=?, CRE
ATE_DATE=?, UPDATE_DATE=? where ID=?

Debug level Hibernate log excerpt:

this is oracle error - you have any column with less length than string
for example, you have LASTNAME varchar2(5) and insert string '123456'

regards

The funny thing is, the code works when I execute it from a testclass (JUnit).
But when I run it from the business delegate (giving the same argument value as in test class), I get the same error.

try junit test with parameter length > length column in database (or form oracle sql) and you get this error
double check value in business delegate (all values before update to database)

I have localized the problem.
In the action class I use the delegate to collect data with hibernate form the db.
I fill 3 lists with data gathered from db. (3 db operations)
2 lists are very similar, they connect to the same table (workmate). When I comment out one of the operations (doesn't matter which one), I don't get no errors anymore.
As you see in the generated SQL, hibernate tries an update! instead of select when both operations a uncommented.
This also happened with the Critera, the Query and the SQLQuery.