Dambudziko guru nderekuti django annotate datetime field to char haishande nemamwe minda yemazuva. Semuenzaniso, kana uine munda unonzi "created_at" uye ukaedza kuitsanangura neCharField kirasi, django haizokubvumiri kuchengetedza data rako.
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>
Datetime muDjango
Django inopa yakanakira datetime mhando inogona kushandiswa kumiririra misi nenguva.
Kugadzira chinhu chenguva, shandisa iyo datetime constructor:
>>> kubva django.utils.datetime import datetime >>> d = datetime(2015, 11, 25) >>> d 2015-11-25 00:00:00
Mienzaniso ye datetime code
Inotevera rondedzero yemuenzaniso datetime kodhi muDjango.
kubva django.utils.datetime import datetime kubva django.utils.translation import gettext_lazy as _ from django.core.urlresolvers import reverse from django.db import models class User(models.Model): first_name = models.CharField(max_length=30, blank=Chokwadi, chisina basa=Nhema) last_name = mhando.CharField(max_length=30, blank=Chokwadi, nullable=Nhema) email = mhando.EmailField() def __str__(self): return self._first_name +' ' + self._last_name + '@' + iwe._email