I am trying to filter a DateTimeField
comparing with a date. I mean:
MyObject.objects.filter(datetime_attr=datetime.date(2009,8,22))
I get an empty queryset list as an answer because (I think) I am not considering time, but I want "any time".
Is there an easy way in Django for doing this?
I have the time in the datetime setted, it is not 00:00
.
This question is related to
python
django
datetime
filter
django-queryset
Model.objects.filter(datetime__year=2011, datetime__month=2, datetime__day=30)
assuming active_on is a date object, increment it by 1 day then do range
next_day = active_on + datetime.timedelta(1)
queryset = queryset.filter(date_created__range=(active_on, next_day) )
As of Django 1.9, the way to do this is by using __date
on a datetime object.
For example:
MyObject.objects.filter(datetime_attr__date=datetime.date(2009,8,22))
In Django 1.7.6 works:
MyObject.objects.filter(datetime_attr__startswith=datetime.date(2009,8,22))
See the article Django Documentation
ur_data_model.objects.filter(ur_date_field__gte=datetime(2009, 8, 22), ur_date_field__lt=datetime(2009, 8, 23))
YourModel.objects.filter(datetime_published__year='2008',
datetime_published__month='03',
datetime_published__day='27')
// edit after comments
YourModel.objects.filter(datetime_published=datetime(2008, 03, 27))
doest not work because it creates a datetime object with time values set to 0, so the time in database doesn't match.
person = Profile.objects.get(id=1)
tasks = Task.objects.filter(assigned_to=person, time_stamp__year=person.time_stamp.utcnow().year)
all my model do have time_stamp so I used the person objects to obtain the current year
There's a fantastic blogpost that covers this here: Comparing Dates and Datetimes in the Django ORM
The best solution posted for Django>1.7,<1.9 is to register a transform:
from django.db import models
class MySQLDatetimeDate(models.Transform):
"""
This implements a custom SQL lookup when using `__date` with datetimes.
To enable filtering on datetimes that fall on a given date, import
this transform and register it with the DateTimeField.
"""
lookup_name = 'date'
def as_sql(self, compiler, connection):
lhs, params = compiler.compile(self.lhs)
return 'DATE({})'.format(lhs), params
@property
def output_field(self):
return models.DateField()
Then you can use it in your filters like this:
Foo.objects.filter(created_on__date=date)
EDIT
This solution is definitely back end dependent. From the article:
Of course, this implementation relies on your particular flavor of SQL having a DATE() function. MySQL does. So does SQLite. On the other hand, I haven’t worked with PostgreSQL personally, but some googling leads me to believe that it does not have a DATE() function. So an implementation this simple seems like it will necessarily be somewhat backend-dependent.
Hm.. My solution is working:
Mymodel.objects.filter(date_time_field__startswith=datetime.datetime(1986, 7, 28))
Here is an interesting technique-- I leveraged the startswith procedure as implemented with Django on MySQL to achieve the result of only looking up a datetime through only the date. Basically, when Django does the lookup in the database it has to do a string conversion for the DATETIME MySQL storage object, so you can filter on that, leaving out the timestamp portion of the date-- that way %LIKE% matches only the date object and you'll get every timestamp for the given date.
datetime_filter = datetime(2009, 8, 22)
MyObject.objects.filter(datetime_attr__startswith=datetime_filter.date())
This will perform the following query:
SELECT (values) FROM myapp_my_object \
WHERE myapp_my_object.datetime_attr LIKE BINARY 2009-08-22%
The LIKE BINARY in this case will match everything for the date, no matter the timestamp. Including values like:
+---------------------+
| datetime_attr |
+---------------------+
| 2009-08-22 11:05:08 |
+---------------------+
Hopefully this helps everyone until Django comes out with a solution!
This produces the same results as using __year, __month, and __day and seems to work for me:
YourModel.objects.filter(your_datetime_field__startswith=datetime.date(2009,8,22))
Mymodel.objects.filter(date_time_field__contains=datetime.date(1986, 7, 28))
the above is what I've used. Not only does it work, it also has some inherent logical backing.
Such lookups are implemented in django.views.generic.date_based
as follows:
{'date_time_field__range': (datetime.datetime.combine(date, datetime.time.min),
datetime.datetime.combine(date, datetime.time.max))}
Because it is quite verbose there are plans to improve the syntax using __date
operator. Check "#9596 Comparing a DateTimeField to a date is too hard" for more details.
Now Django has __date queryset filter to query datetime objects against dates in development version. Thus, it will be available in 1.9 soon.
Here are the results I got with ipython's timeit function:
from datetime import date
today = date.today()
timeit[Model.objects.filter(date_created__year=today.year, date_created__month=today.month, date_created__day=today.day)]
1000 loops, best of 3: 652 us per loop
timeit[Model.objects.filter(date_created__gte=today)]
1000 loops, best of 3: 631 us per loop
timeit[Model.objects.filter(date_created__startswith=today)]
1000 loops, best of 3: 541 us per loop
timeit[Model.objects.filter(date_created__contains=today)]
1000 loops, best of 3: 536 us per loop
contains seems to be faster.
Source: Stackoverflow.com