[Koha] Location and item information (Marc 952) from Koha 2.x to 3.14

[Giuseppe Angilella]

Dear Chris,

briefly: it works! many thanks for your kind advice! :-)

Now, a more extensive summary for the possible benefit of other future 
passers-by (and for my own reference).

My problem was I could not properly edit existing items (or edit newly 
added items) for biblio records belonging to either of two co-existing 
Koha frameworks. "Old" framework complies with Koha 2.x (and has been 
inherited by a problematic backup, not properly upgraded for various 
reasons, some of which disastrous), while "new" framework complies with 
Koha 3.14 (my present installation). Old framework is my current default 
here (as most of my records still belong to that framework).

Chris pointed out that frameworks prior to 3.x collected item 
specifications in some subfields of the MARC 952 tag, already in the MARC 
record (both binary and xml), while more recent frameworks deal with (a 
lot of more) item information only within the "items" mysql table of the 
Koha database. However, individual columns of such table are mapped onto 
specific 952.x subfields. This is indeed described in detail here:

http://wiki.koha-community.org/wiki/Holdings_data_fields_(9xx)

Chris suggested that I should first remove/strip all items information 
from the MARC record of each biblio record, which can be done (with some 
care) through the migration script

misc/maintenance/remove_items_from_biblioitems.pl --run

(reminder: prepend sudo and the appropriate environment variables, such as 
PERL5LIB=/usr/share/koha/lib KOHA_CONF=/etc/koha/sites/<your Koha 
instance>/Koha-conf.xml )

(individual records can be modified by adding the a command parameter such 
as --where="biblioitemnumber=2388" ; this follows a MySQç syntax)

Rebuild the zebra index with sudo koha-rebuild-zebra -v -f

Then, I had to modify existing Koha-to-MARC mappings in the old framework 
for nearly all 952.x subfields, and add all the ones which existed in the 
new framework but were absent in the old framework, so that all subfields 
under the 952 tag looked identical in both the old and the new framework. 
(New framework supersedes the old.)

The zebra index must be rebuilt again (I did it several times, as I kept 
adding/editing subfields, in order to see whether things were working 
properly).

I can now edit/add existing/new items in the new+old/new framework, and 
see them in the Opac at the correct position (no date showing in the place 
of replacement cost or itemnumber instead of a URI ... ).

Many thanks once more!

Giuseppe.