[ome-devel] Hibernate PropertyAccessExcpetion when creating WellSamples in 4.0.1

[josh.moore at gmx.de]

Bernhard Holländer writes:
 > Hi Josh!

Hallo.

 > > The change moving to 4.0.x is that the relation Well->WelSample is now
 > > ordered, so that users can change the display of an entire Plate to
 > > use the same field.

 > Ah, that's interesting. Could you please elaborate a little bit more
 > on how this is achieved. I would have been using the WellSample's
 > timepoint as a field counter to select the same field for an entires
 > Plate.

On import, each well sample is added to the well in the same order. So
wellA.getSample(1) and wellB.getSample(1) will return related
fields. Note: in the 4.1 database (currently trunk), there is a new
field "Plate.defaultSample" which can be used to store the users
choice of the current Well.wellSample index. This will be released
before the meeting in Paris (May 19-20).

 > > Though this exception is an abomination, Hibernate is telling you that
 > > it's not possible to save the WellSample without it's Well instance
 > > loaded. This makes sense since the Well.wellSamples List needs to be
 > > loaded so that the "WellSample.well_index" column can be properly
 > > initialized.
 > 
 > I assume the well_index field is set automatically and not accessible
 > through the object?

Exactly. Part of Hibernate's magic.

 > > To do so, re-order your saves to save the Wells rather than the
 > > WellSamples.
 > 
 > Your proposal is fine, however, in our application one creates plates
 > and all the wells before assigning samples taken in the well. In
 > particular if a plate is measured multiple times I wouldn't create
 > different well sets and have to assign well samples to existing wells.
 > I try if it's possible to load the existing well, add a well sample
 > and save the modified well to insert the new sample. If you see a
 > problem in this approach, please let me know.

This should work. You'll have to be careful about keeping your objects
loaded and up-to-date, but that's standard fare.

 > Thanks! Bernhard

No problem.
~Josh.