Hi Sergio,

about problems related to big tables (select * from $table_name ... ):
I think using jdbc1.0 there's no a *pratical* solution (that I know) to 
retrieve a subset of records from a table (getting x records from table y 
starting at position z).
Anyway, Henner encapsulated the data access stuff used by event classes into 
the org.dbforms.event.datalist.dao.DataSourceXXX classes (that uses also a DAO 
design pattern). So I suppose it's possible to:

a) use the current DatasourceJDBC DAO class for JDBC1.0
c) make another "DatasourceJDBC2.0" class that could use JDBC2.0 and its 
resultSet cursor stuff... example code at: 

http://pow2toolkit.sourceforge.net/
http://prdownloads.sourceforge.net/pow2toolkit/navigation_20021216.zip?download

it uses a *JDBC2.0* data list handler implementation (Henner used a simplified 
pattern for the current org.dbforms.event.datalist package).

See [http://www.theserverside.com/resources/article.jsp?l=DataListHandler] for 
the updated version of the original article by Claudio Fratarcangeli.

I *removed* the "long-lived open database connections" stuff - I prefer the 
simple "open connection / fire query / close connection" paradigm for simplicity
(also to avoid to burn all the db connections)

There's a brute example JSP page that uses the dataHandler to navigate a 
resultSet - see the ./var/web/index.jsp page

Let me know.

I proposed this stuff time ago but it will have forced DbForms to switch 
completely to JDBC2.0 - not an intelligent solution ;^) 

But now, using a factory pattern, having decoupled event classes from concrete 
datasources... 

Regards,
Luca


> Henner Kollmann wrote:
> > Hi Sergio,
> > 
> > Have you ever tried the build in filter/sorting features in dbforms?
> > They can handle something like this statements. No need to build own
> > filter 
> > Tags? Or are they not flexible enough for your needs? Where is the
> > problem with the builtin system? Could we extend the builtin system to
> > fit your needs?
> > 
> the tags are about user interaction, not about on how a filter is 
> applied, anyway, in the new event subsys I could map this in the 
> whereClause attribute.
> For me the problem is not the filter implementation, we can find a more 
> clean solution here, but the issue on dbform not fit by-design against 
> big tables.
> 
> cheers,
> Sergio Moretti
> 
> 
> 
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