Hi Malcolm!
Well, as you say, the range lookup simplifies the code.
I am using MySQL and adding a timedelta of 1 day to a date object and
comparing the range with my datetime field works indeed as expected.
Thanks for your help. It's been very instructive. ;)
Regads, Stefan
Malcolm Tredinnick escribió:
On Thu, 2009-01-29 at 09:48 +0100, Stefan Tunsch wrote:
Well, first of all I can't believe I've overlooked the __in field
lookup... I wasn't aware of it's existance. Sorry.
Regarding the __year, __month and __day lookups I'm using in my code:
I do it because I want to filter all datetime objects of a specific
day. I want to filter all datetime objects like
datetime.datetime(2009, 1, 29, 12, 33, 41, 234000) that are in a day
like datetime.date(2009, 1, 29).
I would want to do something like
mydatetimefield__date=datetime.date(2009, 1, 29) but since that option
does not exist, I am doing this strange thing with year, month and
day.
Since you've just discovered one new lookup type, it's not going to
shock you that there are other good ones out there, too. Today would be
a good day to learn about "__range":" pass in the midnight and 23:59:59
on the day in question and you're down to two lookups. Or use __gte
midnight and __lt midnight on the following day.
In fact, most databases will treat a date range as being between the two
midnights for datetime columns (SQLite is a little fussy there, but
MySQL and PostgreSQL behave nicely). So, Q(foo__range=(<day1>, <day1 +
one day>)) will likely do what you want.
The only reason I'm emphasising these alternatives is that, if you're
doing those queries a lot and need to index those columns for speed,
setting up an index to allow efficient date range comparisons is easier
than creating a functional index for each of the year, month and date
lookups (and, if you're using MySQL, say, you can't even do functional
indexes). Plus, it's a heck of a lot easier to debug at the Python level
with a single datetime object that three variables that have to be
train-wrecked together to work out the date each time.
Regards,
Malcolm
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