[wiki:Haiti]
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== Data Migration ==

We want to be able to migrate data from Prod to Dev so that Testers / Documenters have real data to play with.

Also want to be able to migrate from the current sqlite backend to [wiki:InstallationGuidelinesMySQL MySQL]

=== CSV ===
Beware DB locks!
 * Don't keep Web2Py shell open longer than necessary

{{{
python web2py.py -S prod -M
db.export_to_csv_file(open('db.csv','wb'))
Ctrl+D
}}}

Remove reference Tables from CSV file (don't want to import duplicates!)

{{{
python web2py.py -S dev -M
db.import_from_csv_file(open('db.csv','rb'))
db.commit()
Ctrl+D
}}}

==== Changing a Column type in Sqlite live ====
sqlite handles live migrations pretty well, however if there is existing data then a conversion from string to integer can cause problems.
For a development system, the easiest solution is simply to remove all {{{databases/*}}} & restart, however this isn't possible for a live system:
{{{
vim /home/haiti/prod/models/00_db.py
    migrate = True

cd /home/haiti/prod
bzr pull

cd /home/haiti/web2py
python web2py.py -S prod -M

db(db.or_organisation.id > 0).select().export_to_csv_file(open('orgs.csv','wb'))
db.or_organisation.drop()
db.commit()
Ctrl+D

python web2py.py -S prod -M

db.or_organisation.import_from_csv_file(open('orgs.csv','rb'))
db.commit()
Ctrl+D

/etc/init.d/apache2 force-reload

vim /home/haiti/prod/models/00_db.py
    migrate = False
}}}

If the system is being heavily used, need to put up a holding page during this time to prevent data entry.
For switching on maintenance.
{{{
cd /home/haiti
./maintenance.on
}}}
For switching off maintenance.
{{{
cd /home/haiti
./maintenance.off
}}}
=== Web Services ===
Better to avoid locks & do without SSH login

 * http://localhost:8000/sahana/gis/location/create?format=xml&fetchurl=http://haiti.sahanafoundation.org/prod/gis/location.xml
 * http://localhost:8000/sahana/pr/person/create?format=xml&fetchurl=http://haiti.sahanafoundation.org/prod/pr/person.xml
 * http://localhost:8000/sahana/or/organisation/create?format=xml&fetchurl=http://haiti.sahanafoundation.org/prod/or/organisation.xml
 * http://localhost:8000/sahana/or/office/create?format=xml&fetchurl=http://haiti.sahanafoundation.org/prod/or/office.xml
 * http://localhost:8000/sahana/or/contact/create?format=xml&fetchurl=http://haiti.sahanafoundation.org/prod/or/contact.xml

   * [wiki:S3XRC]
   * Currently needs to be done resource by resource (JOINed tables can be done together as Components of main resource)
    * need to do referenced tables before the tables which refer to them
    * migrate the locations first (using the xml interface), you can later migrate the orgs and offices together (through Component JOIN)
   * Ideally we want to develop a way of having all tables loaded together into RAM, refs fixed-up & then imported to db together

=== Synchronisation ===
Best longer term as we want to be able to have this functionality exposed to UI.

 * BluePrintSynchronisation - which is to be migrated to standard S3XRC Web Services anyway


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[wiki:Haiti]