db backends supports usecs feature in get_db_prep_lookup

[wei guangjing]

The supports usecs feature not use in DateTimeField get_db_prep_lookp, so Datetime lookup will fail use MS SQL Server backend.
For example:

s = Session.objects.get(
                session_key = self.session_key,
                expire_date__gt=datetime.datetime.now()
            )

[wei guangjing]

fix supports usecs in DatetimeField, DateField, TimeField in get_db_prep_lookup

[Adam Vandenberg]

There is no built-in SQL Server backend (anymore); if you could log a bug with a repro case against the specific backend (django-pyodbc, django-mssql, etc.) that would be greatly appreciated (by the maintainers of those projects.)

[Alex Gaynor]

I believe wgj is referring to an external backend.

[Ramiro Morales]

This would be solved in a more clean and generic way by #7560 that is targeted at the 1.0 beta.

(The addition of the supports_usecs feature was part of #7420 that was partially applied in [7643], the intent was coincidentally facilitate the creation of an external MS SQL Server backend. But the feature wouldn't be needed anymore once #7560 lands.)

[Adam Vandenberg]

Very much +1 for #7560 (as I maintain the django-mssql backend...)

[Malcolm Tredinnick]

Yes, #7560 is the way we're going. I'm going to close this one as a "duplicate" of that (since there's not a "better solved by..." resolution).