El martes, 17 de abril de 2018, 9:11:23 (UTC-3), Josh Smeaton escribió: > > Have you looked into using Cast for this particular query to see if it > passes? > > https://docs.djangoproject.com/en/2.0/ref/models/database-functions/#cast > > Cast(RawSQL('%s', ['value']), CharField(max_length=10) ? > > If that worked, then perhaps you could find a clever way to wrap problem > expressions, or at least document the workaround for your users. >
Ok, it worked rigth. It is a good started point and solve the problem. I will need to dig a little more to found out a better solution. Thanks. > > On Tuesday, 17 April 2018 21:12:09 UTC+10, Maximiliano Robaina wrote: >> >> >> Hi Shai, >> >> Thank for the tip >> >> El martes, 17 de abril de 2018, 3:01:30 (UTC-3), Shai Berger escribió: >>> >>> Hi Maximiliano, >>> >>> On Sat, 14 Apr 2018 19:25:48 -0700 (PDT) >>> Maximiliano Robaina <maxir...@gmail.com> wrote: >>> >>> > Hi, >>> > >>> > Testing expressions test app, the query generated into >>> > BasicExpressionsTests.test_annotate_values_filter method: >>> > >>> > companies = Company.objects.annotate( >>> > foo=RawSQL('%s', ['value']), >>> > ).filter(foo='value').order_by('name') >>> > >>> > Generate: >>> > >>> > 'SELECT "EXPRESSIONS_COMPANY"."ID", "EXPRESSIONS_COMPANY"."NAME", >>> > "EXPRESSIONS_COMPANY"."NUM_EMPLOYEES", >>> > "EXPRESSIONS_COMPANY"."NUM_CHAIRS", "EXPRESSIONS_COMPANY"."CEO_ID", >>> > "EXPRESSIONS_COMPANY"."POINT_OF_CONTACT_ID", ? AS "FOO" FROM >>> > "EXPRESSIONS_COMPANY" WHERE ? = ? ORDER BY >>> > "EXPRESSIONS_COMPANY"."NAME" ASC' >>> > >>> > This sql command has 3 params (?), two of which are out of where >>> > clause. >>> > >>> > ? AS "FOO" >>> > >>> > WHERE ? = ? >>> > >>> >>> A few years ago something similar was causing issues with the Oracle >>> backend. To resolve it, Mariusz added a clevar hack, relying on named >>> parameters -- he made sure that if the same parameter value is used >>> more than once, then the statement re-uses the parameter name, passing >>> the value only once. So, in your case, the equivalent would be >>> something like >>> >>> ... >>> "EXPRESSIONS_COMPANY"."POINT_OF_CONTACT_ID", %arg1 AS "FOO" FROM >>> "EXPRESSIONS_COMPANY" WHERE %arg1 = %arg1 ORDER BY >>> "EXPRESSIONS_COMPANY"."NAME" ASC' >>> >>> with >>> >>> cursor.execute(sql, [], arg1='value') >>> >>> This was relatively easy to do in the Oracle backend, which has always >>> used named parameters under the hood (though the idea to do it was, in >>> my opinion, surprising and brilliant). If Firebird supports them, you >>> may be able to borrow this solution. >>> >>> Shai >>> >> >> Ok, but it is a cx_Oracle implementation. >> Unfortunately fdb (the firebird python driver) doesn't support this and, >> in any case, is a FirebirdSQL limitation. [1] >> >> Regards. >> >> >> [1] >> https://stackoverflow.com/questions/37348807/data-type-unknown-in-case-expression-with-only-parameters-as-values >> >> >> > -- You received this message because you are subscribed to the Google Groups "Django developers (Contributions to Django itself)" group. To unsubscribe from this group and stop receiving emails from it, send an email to django-developers+unsubscr...@googlegroups.com. To post to this group, send email to django-developers@googlegroups.com. Visit this group at https://groups.google.com/group/django-developers. To view this discussion on the web visit https://groups.google.com/d/msgid/django-developers/a378e035-d12e-473c-8da1-d6f1190ce3b3%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.