Hibernate and SQL Requests

gaetmail · **Joined:** Fri Sep 30, 2005 6:15 am **Posts:** 50

Hello,

I'm new to hibernate and before to test it I have some questions about
technical features :

1 - What I know is that Hibernate is caching data but what happen if I
update a data from SQL directly or by another application? Hibernate is not
up to date anymore?

2 - Is it possible to trace all the request (in SQL format) that Hibernate
send to the databases (with the date and hour would be nice)

Thanks for your help!

max · **Posted:** Fri Sep 30, 2005 9:15 am

1 - If you want to learn: read the docs ;)
If you just want to think you know then: of course if data is changed
in the database then hibernates data will be out of date - that is also
the case for any other jdbc access - and sometimes that is even what you want. But please go read the documentation about transaction isolation and session identity; there are naturally mechanism for
ensuring you have the data you want/need.

2 - enable sql logging and configure your underlying logging system.
Again its in the docs.

/max

gaetmail · **Joined:** Fri Sep 30, 2005 6:15 am **Posts:** 50

Hello,

Thanks for reply max.
Maybe I was not clear, but I can see SQL on stdout but I can't see the columns values. I have the character '?' instead...

Is it possible to see the complete SQL request run against the database and not those '?'

Thanks for help!

max · **Posted:** Thu Oct 06, 2005 1:21 pm

Its in the FAQ

gaetmail · **Joined:** Fri Sep 30, 2005 6:15 am **Posts:** 50

Thanks Max,

maybe I'm a littlbe bit stupid but I can't find the answer to my question in the FAQ...could you please send me the link as it seems you have the answer...

Thanks for help

max · **Posted:** Fri Oct 07, 2005 5:05 am

http://www.hibernate.org/hib_docs/v3/re ... on-logging

sorry - not in faq, but the obvious place in the docs

gaetmail · **Joined:** Fri Sep 30, 2005 6:15 am **Posts:** 50

Ok thanks!

For users with same questions I didn't managed to see the complete SQL statement but I got the prepared statement with its JDBC parameters.

Just ensures that you have those properties set as shown below in your log4j.properties :

log4j.logger.org.hibernate.SQL=debug
log4j.logger.org.hibernate.type=debug

MAX : do you think there is a better solution where I can get the full SQL statement executed on the database directly?

Thanks for help

max · **Posted:** Fri Oct 07, 2005 5:46 am

use p6spy or similar.

but it will never be precisly the same since embedded constants in sql is not always the same as parameter based queries (escaping and other things)