Re: Re: Support for H2Database

Hello Harry,

Please do check out from subversion, not the zipped versions.  I only 
create the latter occasionally, and you are supporting a new database 
which may require tweaks.    I have already changed the mode to QUERY 
for H2 in subversion.  Subversion is easy to use.  Download the svn 
client and then run the check out command in the README.

I can see that the LOCK_TIMEOUT might get the tests to pass by 
essentially turning off locking, although I am surprised H2 did not 
throw an exception -- have a look at the output.  But I think that H2 
may have some locking (unlike HSQL) so maybe try instead to change 
supportsLocking() as suggested below.  That would be a better solution.

Anthony


At 10:43 PM 3/10/2008, hkara1 wrote:

>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 
><mailto:SimpleORM%40yahoogroups.com>[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:
> >
> >'aced00057e72002173696d706c656f726d2e6578616d706c65732e456d706c6f79 
> 656524455479706500000000000000001200007872000e6a6176612e6c616...
> > >[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><mailto:SimpleORM%40yahoogrou 
> ps.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><mailto:SimpleORM%40yaho 
> ogroups.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>h 
> ttp://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.
> >
>
>

Dr Anthony Berglas, [email protected]       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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