Hi Mike, On Tue, Aug 15, 2023 at 4:30 AM Mike Dewhirst <mi...@dewhirst.com.au> wrote:
> Found a great article by Adam Johnson written in February ... > > > https://adamj.eu/tech/2023/02/23/migrate-django-postgresql-ci-fields-case-insensitive-collation/ > This is a great reference. It helped me out with the migration from postgresql ci fields to db collations. Everything about this is new for me as well. I'm sure the db collation strategy is more powerful and I can see the benefits. However, the postgresql ci fields were way easier to implement. Right now I'm testing it out on a smaller project. One problem that I'm currently facing is that exposing some fields that have the db_collation configuration to django-filters or to Django Admin search parameters are causing an exception: NotSupportedError nondeterministic collations are not supported for LIKE This is the collation that I'm using: CreateCollation( "case_insensitive", provider="icu", locale="und-u-ks-level2", deterministic=False, ) Anyway, all the icu / und-u-ks stuff look a little bit confusing. It would be good to have some guidelines or some quick recipes on the docs that would help us out making the migration :-) Kind regards, Vitor > > > Covers all the bases. > > Thank you Adam > > Cheers > > Mike > > On 7/08/2023 12:28 pm, Mike Dewhirst wrote: > > On 6/08/2023 9:17 pm, Chetan Ganji wrote: > > Thanks Chetan > > I have seen that 'icu' and 'und-whatever...' in various places on the web > - so it seems to be spreading - but I haven't had the brainspace to > understand it yet. > > I'll try an experiment with provider='C' and locale='C' because that is > how most of my databases are already established. If that passes my tests I > might move on to other things. > > From what I can see, PostgreSQL are likely to deprecate citext as > inelegant. That would be why Django has deprecated it. > > Thanks again. > > Mike > > Check this out. > https://gist.github.com/hleroy/2f3c6b00f284180da10ed9d20bf9240a > > # According to Django documentation, it’s preferable to use > non-deterministic collations > # instead of the citext extension for Postgres > 12. > # Example migation to create the case insensitive collation > class Migration(migrations.Migration): > operations = [ > CreateCollation( > 'case_insensitive', > provider='icu', > locale='und-u-ks-level2', > deterministic=False > ) > ] > # Example model using the new db_collation parameter introduced with > Django 3.2 > class Tag(models.Model): > name = models.CharField(max_length=50, db_collation='case_insensitive') > class Meta: > ordering = ['name'] > def __str__(self): > return self.name > > Regards, > Chetan Ganji > +91-900-483-4183 > ganji.che...@gmail.com > http://ryucoder.in > > > On Sun, Aug 6, 2023 at 12:32 PM Mike Dewhirst <mi...@dewhirst.com.au> > wrote: > >> On 5/08/2023 7:58 pm, Chetan Ganji wrote: >> >> Hi Mike >> >> RE: The primary use case is to establish case-insensitivity when checking >> names - including usernames, company names and abbreviations/acronyms. >> >> I dont know anything about db_collation. >> >> >> Me neither >> >> Below 4 lookups should solve most common scenarios. >> >> >> Actually that was how I did it originally. I switched to using the >> PostgreSQL CI field because it is all done in the database - much faster - >> and my code is much reduced and therefore fewer possibilities for bugs etc. >> >> Judging from the Django release notes and the PostgreSQL docs there >> should be a straightforward answer to my question. Researching the correct >> answer is complex enough to make me ask here first. >> >> Cheers >> >> Mike >> >> https://docs.djangoproject.com/en/4.2/ref/models/querysets/#field-lookups >> >> >> >> Regards, >> Chetan Ganji >> +91-900-483-4183 >> ganji.che...@gmail.com >> http://ryucoder.in >> >> >> On Sat, Aug 5, 2023 at 1:35 PM Mike Dewhirst <mi...@dewhirst.com.au> >> wrote: >> >>> The following warning triggered a bit of research which looks like a >>> significant amount of study will be required to find the collation needed >>> ... >>> >>> >>> django.contrib.postgres.fields.CICharField is deprecated. Support for it >>> (except in historical migrations) will be removed in Django 5.1. >>> HINT: Use CharField(db_collation="…") with a case-insensitive >>> non-deterministic collation instead. >>> >>> >>> Does anyone have experience they would like to share? What replaces that >>> ellipsis? >>> >>> The primary use case is to establish case-insensitivity when checking >>> names - including usernames, company names and abbreviations/acronyms. >>> Maybe there is a better way to handle that? >>> >>> This is my typical PostgreSQL database spec ... >>> >>> CREATE DATABASE xxxx >>> WITH >>> OWNER = miked >>> ENCODING = 'UTF8' >>> LC_COLLATE = 'C' >>> LC_CTYPE = 'C' >>> TABLESPACE = pg_default >>> CONNECTION LIMIT = -1 >>> IS_TEMPLATE = False; >>> >>> Many thanks for any help >>> >>> Cheers >>> >>> Mike >>> >>> -- >>> 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 view this discussion on the web visit >>> https://groups.google.com/d/msgid/django-users/2eccab9e-e296-55e0-05de-e8d4cf708262%40dewhirst.com.au >>> <https://groups.google.com/d/msgid/django-users/2eccab9e-e296-55e0-05de-e8d4cf708262%40dewhirst.com.au?utm_medium=email&utm_source=footer> >>> . >>> >> -- >> 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 view this discussion on the web visit >> https://groups.google.com/d/msgid/django-users/CAMKMUjuxfeV5m4QiPz1jEyh7fRobqZn7SCp4dnXnjrSOBirh7Q%40mail.gmail.com >> <https://groups.google.com/d/msgid/django-users/CAMKMUjuxfeV5m4QiPz1jEyh7fRobqZn7SCp4dnXnjrSOBirh7Q%40mail.gmail.com?utm_medium=email&utm_source=footer> >> . >> >> >> >> -- >> Signed email is an absolute defence against phishing. This email has >> been signed with my private key. If you import my public key you can >> automatically decrypt my signature and be sure it came from me. 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This email has > been signed with my private key. If you import my public key you can > automatically decrypt my signature and be sure it came from me. Your > email software can handle signing. > > > -- > Signed email is an absolute defence against phishing. This email has > been signed with my private key. If you import my public key you can > automatically decrypt my signature and be sure it came from me. 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