Inkinga enkulu ukuthi i-django annotate field to char ngeke isebenze nezinkambu ezithile zedethi. Isibonelo, uma unenkambu ebizwa ngokuthi “created_at” futhi uzama ukuyichasisela ngekilasi le-CharField, i-django ngeke ikuvumele ukuthi ulondoloze idatha yakho.
field I have a model with a datetime field and I want to annotate it to a charfield. I tried this: <code>MyModel.objects.values('date').annotate(date_char=CharField()) </code> but it gives me an error: <code>Cannot resolve keyword 'CharField' into field.</code> A: You can use <code>Func</code>: https://docs.djangoproject.com/en/dev/ref/models/expressions/#func-expressions and then use the <code>.format()</code> method on the resulting string to format it however you want (e.g., YYYY-MM-DD): https://docs.python.org/2/library/string.html#formatstrings . Something like this should work: <code>from django.db import models # for Func expression class from django import db # for connection alias, used in Func expression class # create connection alias, used in Func expression class # (this is only necessary if you are using multiple databases) # replace 'default' with your database name if using multiple databases my_conn = db._connections['default'] # create Func expression object that will convert date to string format YYYY-MM-DD my_func = models.Func(my_conn, function='TO_CHAR', template='%(function)s(%(expressions)s::DATE, 'YYYY-MM-DD')') # use my_func in query as follows: MyModelObjects = MyModelObjects .objects .values('date') .annotate(date_char=my_func) </code>
Isikhathi sosuku e-Django
I-Django inikeza uhlobo lwedethi olufanele olungasetshenziswa ukumela amadethi nezikhathi.
Ukuze udale into yedethi, sebenzisa umakhi wesikhathi sosuku:
>>> kusukela ku-django.utils.datetime import datetime >>> d = datetime(2015, 11, 25) >>> d 2015-11-25 00:00:00
Izibonelo zekhodi yedethi
Okulandelayo uhlu lwesibonelo sekhodi yedethi yesikhathi ku-Django.
kusuka ku-django.utils.datetime import datetime from django.utils.translation import gettext_lazy as _ from django.core.urlresolvers import reverse from django.db import model class User(models.Model): first_name = models.CharField(max_length=30, blank=Iqiniso, elingelutho=Amanga) isibongo_isibongo = amamodeli.CharField(max_length=30, blank=Iqiniso, nullable=Amanga) i-imeyili = amamodeli.EmailField() def __str__(self): buyela ngokwakho._first_name +' ' + self._last_name + '@' + ngokwakho._i-imeyili