Description

The function manipulator_validator_unique_together uses IEXACT to check ForeignKey relations. Perhaps this works in MySQL, but in PostgreSQL, it results in the following query:

'SELECT "users"."id", "users"."organization_id", "users"."created_at", "users"."updated_at", "users"."last_login_at",
"users"."username", "users"."password", "users"."password_salt", "users"."is_active", "users"."is_org_admin", 
"users"."first_name", "users"."last_name", "users"."email", "users"."tz", "users"."locale", "users"."home_phone", 
"users"."work_phone", "users"."mobile_phone" FROM "users" INNER JOIN "organizations" ON ("users"."organization_id" = 
"organizations"."id") WHERE "users"."organization_id" ILIKE \'2\' AND "users"."username" ILIKE \'badkins\' ORDER BY 
"organizations"."short_name" ASC, "users"."username" ASC'

which results in the exception ProgrammingError: operator does not exist: integer unknown at character 513 HINT: No operator matches the given name and argument type(s). You might need to add explicit type casts.

The problem occurs on the "users"."organization_id" ILIKE \'2\'. Since organization_id is an integer foreign key, PostgreSQL is complaining that we are trying to pass <int, text> to the ILIKE operator, which expects parameters of type <text, text>. In my case, the organization_id field is a simple ForeignKey in the User model that points to the Organization model. For what it's worth, the unique_together value for my User model is: ('organization', 'username').

I notice that manipulator_validator_unique_together treats fields[0] differently from fields[1:]. I think that the treatment for fields[1:] is correct. In my working copy I changed this line:

        kwargs = {'%s__%s__iexact' % (field_name_list[0], field_list[0].rel.field_name): field_data}

to this instead:

        kwargs = {'%s__pk' % field_name_list[0]: field_data}

and it seems to work correctly. I am certainly not well-versed in the workings of the database wrapper, so it's possible my change is not quite correct.

Thanks in advance for looking into this and resolving it!