tomcat-users mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Steve Kirk" <tomcat-u...@web-startup.co.uk>
Subject RE: GlobalNamingResouces used by other GlobalNamingResources
Date Wed, 27 Oct 2004 16:20:37 GMT
I've just noticed another (more elegant) solution from another post, and
will be changing my code to use it.  As long as your database driver
supports it, try using statement.getGeneratedKeys()

I got this example from
http://www.datadirect.com/products/jdbc/docs/jdbc30feats/index.ssp 
Int rowcount = stmt.executeUpdate (
"insert into LocalGeniusList (name) values ('Karen'),
"employeeID");
ResultSet rs = stmt.getGeneratedKeys (); // Karen's employeeID value is now
available

> -----Original Message-----
> From: Steve Kirk [mailto:tomcat-user@web-startup.co.uk] 
> Sent: Wednesday 27 October 2004 13:29
> To: 'Tomcat Users List'
> Subject: RE: GlobalNamingResouces used by other GlobalNamingResources
> 
> 
> OK now I see your problem.  I have the same issue.  I've 
> worked around it
> with a bit of a hack I'm afraid, and just used the MySQL 
> non-jdbc solution.
> As you say I will pay the price for this sin later, if I ever 
> need to swap
> database.  However I've taken a view that for my specific 
> situation, this is
> unlikely in the medium term.  So instead of investing time in 
> making the
> code completely portable to another database, I've invested time in
> mitigating the impact by genericising my code so that there 
> is only one
> place I will need to make changes.  (Essentially, I've 
> beanified all my
> database tables so that I have a single method that creates 
> rows in any
> table in the database and returns the ID).
> 
> I think portability and re-use are worth investing time and 
> effort in, but
> there is a limit to that, and sometimes, you need to make 
> compromises and
> move on, otherwise you can spend days trying to work around a 
> problem that
> might never happen.
> 
> > -----Original Message-----
> > From: Roland Carlsson [mailto:roland@alfa-moving.se] 
> > Sent: Wednesday 27 October 2004 13:03
> > To: TomcatUsers
> > Subject: Sv: GlobalNamingResouces used by other 
> GlobalNamingResources
> > 
> > 
> > Hi Steve and thanks for you answer.
> > 
> > Try the following scenario.
> > 
> > The problem is to get back the primary key when doing an 
> > insert. Say that
> > you have a master/slave relation between two tables.
> > 
> > You insert a row into master. Then you are going to insert 
> a few rows
> > connected to the master into slave. How do you know the 
> > id-number of your
> > master?
> > 
> > I know that mysql has a non-jdbc soloution for this but since 
> > one of our
> > general design goals are portable code...... So, we have 
> > desided to take the
> > same apporach as Object-Relational Bridge. We created our own 
> > id-generator
> > to handle the problem. But its has created a new set of 
> > problems now when we
> > are going to use multiple web-apps and (in a not so distant 
> > future) mutiple
> > servers.
> > 
> > Regards
> > Roland Carlsson
> > 
> > 
> > 
> > 
> > Den 04-10-27 13.48, skrev "Steve Kirk" 
> > <tomcat-user@web-startup.co.uk>:
> > 
> > > sorry, can't answer specific Q on whether you can access 
> > datasource from
> > > generator.  but it sounds like you are trying to uniquely 
> > ID rows in a
> > > database?
> > > 
> > > if so then the simplest way seems to be to use 
> > auto_increment fields and let
> > > the database handle it.  or are you saying that that isn'y 
> > working - is this
> > > what you mean by "not supporting the database-generated 
> > id-numbers"?  if so
> > > please say more about why its not working.  what database? 
> > code sample?
> > 
> > 
> > 
> ---------------------------------------------------------------------
> > To unsubscribe, e-mail: tomcat-user-unsubscribe@jakarta.apache.org
> > For additional commands, e-mail: tomcat-user-help@jakarta.apache.org
> > 
> > 
> 
> 
> 
> ---------------------------------------------------------------------
> To unsubscribe, e-mail: tomcat-user-unsubscribe@jakarta.apache.org
> For additional commands, e-mail: tomcat-user-help@jakarta.apache.org
> 
> 



---------------------------------------------------------------------
To unsubscribe, e-mail: tomcat-user-unsubscribe@jakarta.apache.org
For additional commands, e-mail: tomcat-user-help@jakarta.apache.org


Mime
View raw message