Sorry for the follow up question, when you say run migration locally, this is running python manage.py makemigrations and python manage.py migrate, right? Please let me know if I got these steps correctly:
- make a postgres test db - changed database settings in settings.py and point it to test db in postgres - If i run makemigrations and migrate, the only db and tables that will be saved in test db are the ones in our models.py Should I modify the models.py to match the fields in the dump file? or should I just check the existing data from the dump file and see which model and fields it fits in our existing system? My only experience with changing backend database in Django was when I changed one of my pet projects db from SQLite to Postgres which I did in settings.py. On Thu, Apr 12, 2018 at 8:59 AM, tango ward <tangowar...@gmail.com> wrote: > At the moment, I am comparing the fields from the dump file and the fields > in our models.py. There are fields that exist on the dump file that are not > yet in our existing model/models that why I want to know if should I modify > the schema of our database to match the dump file of the client. I'm lost > on this, sorry. > > On Thu, Apr 12, 2018 at 8:46 AM, Mike Dewhirst <mi...@dewhirst.com.au> > wrote: > >> On 12/04/2018 9:47 AM, tango ward wrote: >> >>> Hi Mike, >>> >>> >>> Thanks for the advice. >>> >>> May I ask as well, on Django side, since we have already an existing >>> system, how should I adjust the fields that are existing from the dump file >>> to the Django? Should I just add fields in models.py? >>> >> >> Treat that as a separate task. You can do it before the migration or >> after. I would preferdo it afterwards because I am more comfortable with >> Postgres. And I suspect Postgres will be a better fit with Django. >> >> However, I'm not sure what you mean exactly by adjusting fields. Your >> last question above indicates you want to change the schema in an existing >> Django project. You need to consider when the fields need to be changed in >> the context of real-world pressures from your production system users. It >> might need to be sooner rather than later and that may force adjustments >> prior to the move to Postgres. >> >> If there are problems with the existing MySQL system it would be best to >> fix them before switching. >> >> The bottom line is that preparations and testing for the move has to >> happen in parallel with ongoing support and maintenance and possibly >> ongoing development of the production system. When you are ready to switch >> and happy that it will go like clockwork the actual switch can be scheduled >> as a definable task in the ongoing workflow. All developers will have to >> switch at the same time - or prior if they can have access to your >> completed scripts for their personal development databases. >> >> hth >> >> Mike >> >> >>> On Thu, Apr 12, 2018 at 6:42 AM, Mike Dewhirst <mi...@dewhirst.com.au >>> <mailto:mi...@dewhirst.com.au>> wrote: >>> >>> On 11/04/2018 11:40 PM, tango ward wrote: >>> >>> Hi there, >>> >>> This will be my first time to migrate a database in my first >>> programming job. I checked the dump file today and load it in >>> MySQL benchmark to view the ERD. The database that I need to >>> migrate has 48 tables and has existing data already. >>> >>> >>> I would like to know what are the things that I need to do >>> first. I'm gonna test the migration first in my local machine >>> before bringing it to live production. I am currently reading >>> https://wiki.postgresql.org/wiki/Converting_from_other_Datab >>> ases_to_PostgreSQL >>> <https://wiki.postgresql.org/wiki/Converting_from_other_Data >>> bases_to_PostgreSQL>. >>> >>> >>> >>> >>> Any suggestions will be highly appreciated. >>> >>> >>> 1. Do the migration locally >>> >>> 2. Devise some repeatable automated success tests to prove the >>> migration works >>> >>> 3. Set up a new VM as an exact duplicate production machine >>> running MySQL. Use your hosts file to put its IP address somewhere >>> else than the DNS points to. Beware that ACLs often use IP >>> addresses rather than host names. >>> >>> 4. Do the migrations and run the tests on the duplicate machine. >>> Debug as necessary. >>> >>> 5. Announce to users that the system is going down for planned >>> maintenance >>> >>> 6. Remove your hosts file adjustment so your system is back to >>> looking at the real production machine >>> >>> 7. Take production off-line and do a pre-migration dump or backup >>> from which you can restore if things go wrong >>> >>> 8. Do the migration, run the tests then restore service >>> >>> I have done such things in the distant past but not recently. I >>> may have forgotten something but in my opinion items 5 and 7 above >>> are super critical. >>> >>> Good luck >>> >>> Mike >>> >>> >>> >>> Thanks, >>> J >>> -- You received this message because you are subscribed >>> to the >>> Google Groups "Django users" group. >>> To unsubscribe from this group and stop receiving emails from >>> it, send an email to django-users+unsubscr...@googlegroups.com >>> <mailto:django-users%2bunsubscr...@googlegroups.com> >>> <mailto:django-users+unsubscr...@googlegroups.com >>> <mailto:django-users%2bunsubscr...@googlegroups.com>>. >>> To post to this group, send email to >>> django-users@googlegroups.com >>> <mailto:django-users@googlegroups.com> >>> <mailto:django-users@googlegroups.com >>> <mailto:django-users@googlegroups.com>>. >>> Visit this group at >>> https://groups.google.com/group/django-users >>> <https://groups.google.com/group/django-users>. >>> To view this discussion on the web visit >>> https://groups.google.com/d/msgid/django-users/CAA6wQLKcf22a >>> XXKd6xUn%3DT6HOxHLBN7u1xcn%3DOXO3DdL%3D54XSg%40mail.gmail.com >>> <https://groups.google.com/d/msgid/django-users/CAA6wQLKcf22 >>> aXXKd6xUn%3DT6HOxHLBN7u1xcn%3DOXO3DdL%3D54XSg%40mail.gmail.com> >>> <https://groups.google.com/d/msgid/django-users/CAA6wQLKcf22 >>> aXXKd6xUn%3DT6HOxHLBN7u1xcn%3DOXO3DdL%3D54XSg%40mail.gmail. >>> com?utm_medium=email&utm_source=footer >>> <https://groups.google.com/d/msgid/django-users/CAA6wQLKcf22 >>> aXXKd6xUn%3DT6HOxHLBN7u1xcn%3DOXO3DdL%3D54XSg%40mail.gmail. >>> com?utm_medium=email&utm_source=footer>>. >>> For more options, visit https://groups.google.com/d/optout >>> <https://groups.google.com/d/optout>. >>> >>> >>> >>> >> -- >> You received this message because you are subscribed to the Google Groups >> "Django users" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to django-users+unsubscr...@googlegroups.com. >> To post to this group, send email to django-users@googlegroups.com. >> Visit this group at https://groups.google.com/group/django-users. >> To view this discussion on the web visit https://groups.google.com/d/ms >> gid/django-users/07a26b64-9923-f9ee-b6c2-47676d245038%40dewhirst.com.au. >> >> For more options, visit https://groups.google.com/d/optout. >> > > -- You received this message because you are subscribed to the Google Groups "Django users" group. To unsubscribe from this group and stop receiving emails from it, send an email to django-users+unsubscr...@googlegroups.com. To post to this group, send email to django-users@googlegroups.com. Visit this group at https://groups.google.com/group/django-users. To view this discussion on the web visit https://groups.google.com/d/msgid/django-users/CAA6wQLKdJit5eLHCiFSwwoMA0Feg7b69vyRDP_d7u%3D4W0YGkdQ%40mail.gmail.com. For more options, visit https://groups.google.com/d/optout.
