ORM fails in PostgreSQL when you filter with unicode strings. For example:
>>> from django.contrib.auth.models import User
>>> User.objects.filter(username=u'admin')
...
ProgrammingError: ERROR: column "admin" does not exist
SELECT "auth_user"."id","auth_user"."username","auth_user"."first_name","auth_user"."last_name","auth_user"."email","auth_user"."password","auth_user"."is_staff","auth_user"."is_active","auth_user"."is_superuser","auth_user"."last_login","auth_user"."date_joined" FROM "auth_user" WHERE ("auth_user"."username" = admin) ORDER BY "auth_user"."username" ASC
The problem is on psycopg library, here are an example:
>>> from django.db import connection
>>> cursor = connection.cursor()
>>> cursor.execute('SELECT * from auth_user WHERE username = %s', [u'admin'])
...
ProgrammingError: ERROR: column "admin" does not exist
SELECT * from auth_user WHERE username = admin
Ok, it's true... it's not a django error, but for example, in newforms all is unicode... ¿what we do? ¿Use psycopg2? ¿convert all unicodes to ascii in lookups? ¿convert all params on postgresql?. Call is made on django/db/models/query.py, on this sentences:
cursor = connection.cursor()
select, sql, params = self._get_sql_clause()
cursor.execute("SELECT " + (self._distinct and "DISTINCT " or "") + ",".join(select) + sql, params)
