Hello Rainer,
thanks for your instant advice. It does the trick, indeed!
I feel a bit ashamed that I did not realize myself that the driver can be
subclassed…
Thanks,
Vladimir
On 11. 2. 2012, at 23:31, Rainer Döbele wrote:
> Hello Vladimir,
>
> thanks for letting us know.
>
> Indeed the TEXT data type for DDL generation got lost on the way, when we
> removed redundant code.
> This will be easy to fix and I will do that in the next few days.
>
> For you other problem, I suggest the following:
> Please create your own driver class that extends DBDatabaseDriverPostgreSQL
> and pass an instance to this class to the open method of your DBDatabase
> object.
> Now override the method getResultValue(ResultSet rset, int columnIndex,
> DataType dataType)
> and provide you own logic for obtaining the clob value e.g. like this:
>
> if (dataType == DataType.CLOB)
> {
> return rset.getString(columnIndex);
> }
> else return super.getResultValue(...)
>
> If I understood you correctly this should do the trick.
> If you confirm this, then we will modify the Postgre driver code accordingly.
>
> Looking forward to hearing from you
>
> Regards
> Rainer
>
>
>> from: Vladimir Lahoda [mailto:[email protected]]
>> to: [email protected]
>> re: Problems with CLOB in postgresql
>>
>> Hi,
>>
>> I've switched my empire-db (2.2.0) project from Oracle to Postgresql
>> (version 8.4) and encountered two problems with CLOB columns.
>>
>> First, trying to read the CLOB value from the result set using
>> DBReader.getValue() fails with the following error:
>>
>> org.postgresql.util.PSQLException: Bad value for type long : some
>> string value
>> at
>> org.postgresql.jdbc2.AbstractJdbc2ResultSet.toLong(AbstractJdbc2ResultS
>> et.java:2796)
>> at
>> org.postgresql.jdbc2.AbstractJdbc2ResultSet.getLong(AbstractJdbc2Result
>> Set.java:2019)
>> at
>> org.postgresql.jdbc4.Jdbc4ResultSet.getClob(Jdbc4ResultSet.java:43)
>> at
>> org.apache.empire.db.DBDatabaseDriver.getResultValue(DBDatabaseDriver.j
>> ava:490)
>> at org.apache.empire.db.DBReader.getValue(DBReader.java:374)
>>
>> The problem is that DbReader eventually calls JDBC method getClob()
>> which IMHO is not implemented correctly in the postgresql driver. It is
>> recommended to use getString() method on the CLOBs in Postgresql
>> instead. But calling DBReader.getString() does not help either, because
>> it ends up calling getValue().toString(), with the same result as
>> above. The same situation holds for BLOBs as well. Any hints or
>> workarounds, please?
>>
>>
>> The second problem is with the DDL generator, which defines the CLOB
>> column type as CLOB, but this is unsupported by Postgresql and should
>> be TEXT instead. Some googling suggests that this was already fixed for
>> previous versions of empire-db (at least in 2.0.7), but probably the
>> fix got lost in refactorings for version 2.2.0.
>>
>> No other complaints so far ;-) Thanks a lot for this great project and
>> congratulations for promotion to TLP!
>>
>>
>> Regards,
>>
>> Vladimir
