I have a Django project, and I want to save created_at datetime in the database. I generate datetime.now with jdatetime (or Khayyam) python package and try to save this in DateTimeField. But sometimes it raises error because the Gregorian(miladi) date of the entry does not exist. what can I do about this?
In my idea, you can save two model fields.
One is DateTimeField contains gregorian datetime, and
another one, CharField contains converted Jalali to a String value and save it.
The DateTimeField for functionality, e.g., filter between to datetime.
The StringField for representing in response(without overload).
Related
class Test(Model):
time = DateTimeField()
# ...
row = Test.select()[0]
test.time
This returns a string that looks like this: 2017-01-23 01:01:39+01:00. How can I get it as a datetime object instead? Do I have to parse it manually?
Also I would be interested if there is any documentation on how to use the DateTimeField. The official documentation doesn't have anything on it.
Are you using SQLite? If so, SQLite doesn't have a dedicated datetime type, so datetimes are stored as strings in the DB. What peewee will do is recognize certain datetime formats coming out of the DB and convert them to datetime objects. What you need to do is ensure that either:
When you create/save your object, that you assign a datetime object to the field.
When reading back pre-existing data, that the data is in a recognized format.
The formats peewee supports out-of-the-box for datetime field are:
YYYY-mm-dd HH:MM:SS.ffffff
YYYY-mm-dd HH:MM:SS
YYYY-mm-dd
It looks like your has zone info. I'd suggest converting to UTC and dropping the zone info. That should fix it.
Have you tried adding a default like this?
time = DateTimeField(default=datetime.datetime.now())
Or when adding an entry add it as a datetime.datetime object directly:
test = Test(....., time=datetime.datetime.strptime("2018-3-15", '%Y-%m-%d'))
In the second case you don't need to specify anything in the class definition...
I am adding timestamp in my payload and storing it in the database for every record.
Suppose say a part of my payload is {"content":[{"timestamp":"2017-12-12 08:05:30"}]
This is how I process it.
content['timestamp'] = parser.parse(content['timestamp'],dayfirst=True)
My model has timestamp field as :
timestamp = models.DateTimeField(null=True)
When I check in my database it stores timestamp field as :
2017-12-12 13:35:30
Which should be stored as it is as per my requirement. 2017-12-12 08:05:30
i.e it stores the timestamp field + my local timezone(+5:30) hours.
I want it to store the timestamp field as it is.
I tried other posts where they suggest using del os.environ['TZ'].
Any idea what I may have done which causes this or what could I do to avoid this.
Any help is appreciated.
So according to this Question the problem is when django converts datetime to postgres timestamptz in the database.
Postgres prevent timestamp with timezone conversion
So I need to have timestamp field in PostgreSQL
In order to do that , I need to use the answer posted in this question.
Can we have django DatetimeField without timezone?
Where I need to specify USE_TZ = False in the settings.
This makes sure while migrating PostgreSQL considers datetimefield to be converted to timestamp and not timestamptz .
You can set a timezone in settings.py
Here is the list of valid timezones:
http://en.wikipedia.org/wiki/List_of_tz_database_time_zones
You can use
TIME_ZONE = 'Asia/Calcutta'
for UTC+05:30
Reference from Selcuk Answer
I am trying to display set time of Postgres database time to datetime field into Odoo.
I am creating field is that to set the time.
last_modify_article = fields.Datetime("Last Modify Date")
But my DateTime :~ 2017-08-28T08:43:56+0200 is perfectly stored in Postgres database but in Odoo saw in different.
So, my question is that how can I manage the database date-time in the field.
Here is the Postgres Time
And
Here is Odoo field to set datetime in UTC
Actually the database stores the Datetime field according to the system timezone. In Odoo, views which will be automatically converted according to the user's timezone if it is set.
On your images, I can see the time difference id +5:30 ie, Asia/Kolakata timezone. So your custom operations on Datetime field need the proper conversion of Timezone according to the user.
Odoo views and ORM methods are treated the tz with moment.js and the pytz conversions. This is actually a good feature to manage different timezones in Odoo.
You can use astimezone on Datetime objects:
def astimezone(self, tz): # known case of datetime.datetime.astimezone
""" tz -> convert to local time in new timezone tz """
return datetime(1, 1, 1)
or
fields.Datetime.context_timestamp(self, datetime.strptime(value, DEFAULT_SERVER_DATETIME_FORMAT))
Odoo is designed to have the date and time stored as UTC in the database and convert it to the user's timezone on the front-end.
What time zone is set for your user? You can click your name in the top right, then Preferences. Time zone should be shown on the popup form.
You can use pytz library to convert datetime based on user's timezone. See the code sample.
import pytz
import datetime
def current_user_datetime(self):
currenttimezone = pytz.timezone(self.env.context.get('tz'))
user_datetime = datetime.datetime.now(currenttimezone)
self.timefield = user_datetime
I have noticed that when I return records from my SQL database using the following: the_records = records.objects.filter(datetime__contains="2015-01-15"), I get back the wrong records because the timezone is affecting the function call somehow - I know this because if I temporarily disable the timezone, the right records are returned. Can anyone offer assistance on what I should do to fix this problem (I still need to use the timezone).
Regards, Mark
I'm assuming that datetime is a Django DateTime field, and you're trying to get the results that have a value that matches the date '2015-01-15', ignoring the actual time.
In that case, you probably want to do a date query, like: Records.objects.filter(datetime__date=datetime.date(2015, 1, 15))
If you need to query your db with a timezone specific date, you can just create a datetime object that is aware of it's timezone.
Example:
# Get your timezone
from django.utils import timezone
my_timezone = timezone.get_current_timezone()
# Get create your timezone aware datetime object
from datetime import datetime
query_date = datetime(2015,01,15).replace(tzinfo=my_timezone)
# now you can run your query with a timezone specific datetime object
the_records = records.objects.filter(datetime=query_date)
This should solve your issue and get you the accurate results you need.
Please let me know if you still have any questions.
This link has more info related to django timezones if you are interested in learning more.
I have a CharField in my model as well as my database. I want to convert this CharField column to real datetime Django format. I have this insert query like
test.objects.create(voice=m.voice, size=m.size, start_time=get_time.get('min_time'),)
I would like to create a function to solve it, but not sure how to do it. Please help.
I think directly change the character field into datetime field is hard. Your need to do it one by one.
Create a new datetime column e.g. start_datetime
Create a script to convert the start_time from string into datetime object.
Edit all code that depend on start_time
Delete the start_time column
This is the example conversion from string to datetime code.
import time
for obj in Test.objects.all():
obj.start_datetime = time.strptime(obj.start_time, "%d %b %y")
obj.save()
You might want to read this python time library.