[Kmymoney-devel] missing subject

[Fernando Vilas]

On Friday, October 3, 2014 12:29:47 PM Christian Dávid wrote:
> Hi Fernando,
> 
> finally I want to finish the online banking stuff for the database backend.
> So I have more questions…
> 
> Am Sonntag, 21. September 2014, 15:33:46 schrieb Fernando Vilas:
> > > I even think, this behavior will prevent the upgrades to v1, and v7 as
> > > they
> > > call readFileInfo() and new columns were created in that versions. If
> > > you
> > > have to upgrade more versions than just on (vN -> vM | m >= n+2) it will
> > > even fail if you start with any version before v7 (= all possible update
> > > processes).
> > > 
> > > Actually the test databases which I just created (using master branch)
> > > identifies itself as version 6 but it should be v7. This indicates a bug
> > > in
> > > the upgrade process.
> > > 
> > > _ Solution _
> > > 
> > > I would recommend not to use readFileInfo() and writeFileInfo() in any
> > > upgrade methods anymore and just call writeFileInfo() at the end of the
> > > upgrade process. Also the m_hi…Id vars need to be set somewhere.
> > 
> > That sounds reasonable. The system was designed to make upgrades easy, but
> > there are always cases you did not consider. I do not remember us
> > considering  removing columns, just adding/changing them, so this is new
> > territory.
> 
> I think this is a misunderstanding. To solve that: Where/when exactly are
> columns added to the database? I cannot find any piece of code that triggers
> that :(
> 

It looks like I was mistaken. There is code to create new tables, but it is in 
the upgradeToV<num>() calls that the call to generateDDL on the new columns is 
executed. There is probably a good way to abstract it if we want to automate 
the adding of columns. If not, the calls look like what is in upgradeToV1().

> The errors I got are not caused by removed columns (I do not drop any
> column) but it is caused by columns which are going to be created (well,
> actually won't be created, because KMyMoney crashes first…).
> 

The upgradeDb() call that invokes upgradeToV<num>() should take care of adding 
the columns. If it still crashes afterwards, then that is a different bug.

> > > How is the database created if you create a new database from scratch:
> > > 1) Is the most recent database version created directly? Or
> > > 2) do you create a database of version 0 and then call all upgrade
> > > methods?
> > 
> > It should be option 1: just creating the database using the current state
> > of  affairs for tables/views. That definitely simplifies things, but can
> > make testing the upgrade functions non-trivial.
> 
> Has somebody a database (with test data) from version 0? I can just compile
> KMyMoney 4.5, all earlier versions do not compile on my system anymore. Or a
> database of any other version (e.g. 6.0)? That could help me testing.
> 
> We should create some database files and .xml files for each version and
> save them for later test of the upgrade routines.
> 

Yes!!! That has been a gap in our testing until now. I usually just took a 
snapshot of my database and then practiced upgrading until it worked, then did 
it on the master copy. I tended to make a backup first, though. We definitely 
could use a version 0 file for testing the upgrade path as part of the test 
harness.

Also, I hope you don't misinterpret my delays in responses or vague guidance. 
I am in the middle of a stretch of long weeks at $dayjob and have not been 
able to dedicate the time that KMM deserves. I really appreciate that someone 
else is digging into the code and improving it.

Thanks,
Fernando