Re: Support for H2Database

Hi,

I found the timeout parameter for locks, so all the tests run
correctly now.
The timeout can be set by adding the parameter to the jdbc url,
or by issuing a "SET LOCK_TIMEOUT nnn" statement on the current
connection.
For the tests, I have put the following properties in 
%userprofile%\simpleorm.properties :

database.url=jdbc:h2:C:/t/TestSimpleorm;LOCK_TIMEOUT=60000
database.username=sa
database.password=
database.driver=org.h2.Driver

And tests ran like a charm.

Harry

--- In [email protected], Anthony Berglas <anthony@...> wrote:
>
> Hello Harry,
> 
> Thanks for your work on H2, which looks quite good.  I'm thinking we 
> should probably make it the default db in the next release of 
> SimpleORM.  The compatibility with the PostgreSQL might be handy for 
> people like Franck.
> 
> Unlike HSQLDB H2 seems to support locking.  Maybe try override
>          public boolean supportsLocking() {
>                  return true; // was false.
>          }
> It would be interesting to know if that fixes the lock test.
> 
> I do not understand your point about Enum.  The current code is
>    return ((Enum<T>)value).name();
> where .name() returns a string.
> 
> Your Offset/Limit code also works for HSLQDB, so has been added to 
> the SDriverHSQLH2.
> 
> As to registering drivers,  I have added the H2 driver to the current 
> version in subversion.  I strongly suggest that you check out from 
> there.   I have added your updates, please check out and confirm that 
> they work for you.  (The crude code in SDriver that registers them 
> could be improved.)
> 
> Anthony
> 
> 
> At 03:27 AM 1/10/2008, hkara1 wrote:
> 
> >Hi, the unit tests are OK, except for the long transaction test
> >that fails with a lock timeout (this should not be too serious).
> >
> >BUT READ ON !
> >
> >However, the unit tests only work for H2 version 1.0, version 0.9
> >raises some errors, especially for correlated queries. So ONLY USE
> >V. 1.0 (and above, when available) of H2.
> >
> >There is also a problem I encountered in the SFieldEnum class,
> >because H2 tries to write it as Object, and this raises an error :
> >
> >Value too long for column ETYPE:
>
>'aced00057e72002173696d706c656f726d2e6578616d706c65732e456d706c6f79656524455479706500000000000000001200007872000e6a6176612e6c616...
> >[90005-79]
> >
> >Now the column is declared as VARCHAR when SFieldEnum is used, so
> >I guess it should return an object of type String (not of type
> >EnumClass). So the unit test works OK when I add the following
> >method to SFieldEnum :
> >
> >@Override
> >public Object writeFieldValue(Object value) {
> >if (value == null) return null;
> >return value.toString();
> >}
> >
> >And anyway Enums should be transformed to Strings using toString()
> >according to the JDK docs.
> >
> >Here is the driver I have used :
> >
> >/**
> >* The H2 is mostly HSQL (H2 is a fork, by the original author of
HSQLDB)
> >*/
> >public class H2Driver
> >extends SDriverHSQL
> >{
> >@Override
> >protected String driverName() {
> >return "H2 JDBC Driver";
> >}
> >
> >@Override
> >protected OffsetStrategy getOffsetStrategy() {
> >return OffsetStrategy.QUERY;
> >}
> >
> >@Override
> >protected String limitSQL(long offset, long limit) {
> >StringBuffer sb = new StringBuffer();
> >if (limit != Integer.MAX_VALUE) sb.append(" LIMIT "+limit);
> >if (offset > 0) sb.append(" OFFSET "+offset);
> >return sb.toString();
> >}
> >}
> >
> >And in the TestUte class, I have added the driver registration
> >when the properties file gets loaded; this should not be
> >necessary if the H2 driver is built-in
> >
> >...
> >in.close();
> >new H2Driver().registerDriver();
> >...
> >
> >I guess maybe in the future we could "standardize" a bit more
> >the way someone can add a driver for a particular database,
> >without having to include it in the H2 distribution (I am thinking
> >of sqlite, for example, which has peculiar SQL but has some very
> >interesting cross-platform usages, where not all of Simpleorm would
> >work, but sufficiently to be interestin). We could look for a
> >system property like "simpleorm.extra.drivers" and use
> >the class names declared there, for example. This would
> >remove the need to support those external drivers, that would come
> >in separate jars from elsewhere.
> >
> >Hope this helps,
> >
> >Harry
> >
> >--- In 
> ><mailto:SimpleORM%40yahoogroups.com>[email protected], 
> >Anthony Berglas <anthony@> wrote:
> > >
> > > Oops, I see what you have done, just extended HSQL Driver. I'll
> > > refactor a bit and add it.
> > >
> > > Please confirm the unit tests pass.
> > >
> > > Anthony
> > >
> > > At 07:39 PM 25/09/2008, Anthony Berglas wrote:
> > > >Hello Harry,
> > > >
> > > >Thanks for that.
> > > >
> > > >But before I include your code, what about the other things in
> > > >SDriverHSQL? In particular, is the support for SEQUENCES the same
> > > >in H2 as it is in HSQL? Did you remove the code deliberately?
> > > >
> > > >Your loading code is OK, but if you look at the beginning of
> > > >SDriver.java you will see where drivers are loaded
> > > >automatically. I'll do that when your done.
> > > >
> > > >Anthony
> > > >
> > > >At 07:25 PM 23/09/2008, you wrote:
> > > >
> > > >>Hi,
> > > >>
> > > >>I've been using this just as you described, and it works fine.
> > > >>Here is the class I use :
> > > >>
> > > >>package org.hmn.jrsd.demo;
> > > >>
> > > >>import simpleorm.drivers.SDriverHSQL;
> > > >>import simpleorm.sessionjdbc.SDriver;
> > > >>
> > > >>/*
> > > >>*
> > > >>* Cree par Harry Karadimas a 9 sept. 08
> > > >>*/
> > > >>/**
> > > >>* The H2 is mostly HSQL (H2 is a fork, by the original author of
> >HSQLDB)
> > > >>*/
> > > >>public class H2Driver
> > > >>extends SDriverHSQL
> > > >>{
> > > >>@Override
> > > >>protected String driverName() {
> > > >>return "H2 JDBC Driver";
> > > >>}
> > > >>
> > > >>}
> > > >>
> > > >>To use the driver, it must first be registered when the
> > > >>application starts :
> > > >>
> > > >>//we register the H2 driver
> > > >>new H2Driver().registerDriver();
> > > >>
> > > >>You can then connect to the H2 database as usual :
> > > >>
> > > >>try {
> > > >>Class.forName("org.h2.Driver");
> > > >>driverLoaded = true;
> > > >>}
> > > >>catch (Exception ex) {
> > > >>throw new SQLException("Could not load H2 driver ("+ex+")");
> > > >>}
> > > >>Connection cxn = DriverManager.getConnection(url, user, password);
> > > >>
> > > >>I don't really know if that is the best way to do it, however.
> > > >>
> > > >>Harry
> > > >>
> > > >>--- In
> > > >><mailto:SimpleORM%40yahoogroups.com>[email protected],
> > > >>Anthony Berglas <anthony@> wrote:
> > > >> >
> > > >> > Have not done this yet. But if you copy the HSQL driver it
should
> > > >> > only require trivial changes. SimpleORM minimizes database
> > > >>dependent code.
> > > >> >
> > > >> > If you do this and it runs through the test cases then please
> >post it
> > > >> > back to the list and I'll add it to the source.
> > > >> >
> > > >> > Anthony
> > > >> >
> > > >> > At 06:15 AM 23/09/2008, alspaughb wrote:
> > > >> > >Does SimpleORM support H2Database? I can't find an SDriver
> >subclass
> > > >> > >for it.
> > > >> > >
> > > >> > ><<http://www.h2database.com>http://www.h2database.com>http:/ 
> > /www.h2database.com
> > > >> > >
> > > >> > >I like the fact that H2 is lightweight, pure Java, and
> >supports multi
> > > >> > >version concurrency.
> > > >> > >
> > > >> > >Bruce
> > > >> >
> > > >> > Dr Anthony Berglas, anthony@ Mobile: +61 4 4838 8874
> > > >> > Just because it is possible to push twigs along the ground with
> >ones
> > > >>nose
> > > >> > does not necessarily mean that is the best way to collect
firewood.
> > > >> >
> > > >>
> > > >>
> > > >
> > > >Dr Anthony Berglas, anthony@ Mobile: +61 4 4838 8874
> > > >Just because it is possible to push twigs along the ground with
> >ones nose
> > > >does not necessarily mean that is the best way to collect firewood.
> > >
> > > Dr Anthony Berglas, anthony@ Mobile: +61 4 4838 8874
> > > Just because it is possible to push twigs along the ground with ones
> >nose
> > > does not necessarily mean that is the best way to collect firewood.
> > >
> >
> >
> 
> Dr Anthony Berglas, anthony@...       Mobile: +61 4 4838 8874
> Just because it is possible to push twigs along the ground with ones
nose
> does not necessarily mean that is the best way to collect firewood.
>



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