DateTimeField - Django Models - GeeksforGeeks

12 Feb, 2020
DateTimeField is a date and time field which stores date, represented in Python by a datetime.datetime instance. As the name suggests, this field is used to store an object of datetime created in python. The default form widget for this field is a TextInput. The admin uses two separate TextInput widgets with JavaScript shortcuts.
Syntax
field_name = models.DateTimeField(**options)
DateTimeField.auto_nowAutomatically set the field to now every time the object is saved. Useful for “last-modified” timestamps. Note that the current date is always used; it’s not just a default value that you can override.The field is only automatically updated when calling Model.save(). The field isn’t updated when making updates to other fields in other ways such as QuerySet.update(), though you can specify a custom value for the field in an update like that.
Automatically set the field to now every time the object is saved. Useful for “last-modified” timestamps. Note that the current date is always used; it’s not just a default value that you can override.The field is only automatically updated when calling Model.save(). The field isn’t updated when making updates to other fields in other ways such as QuerySet.update(), though you can specify a custom value for the field in an update like that.
DateTimeField.auto_now_addAutomatically set the field to now when the object is first created. Useful for creation of timestamps. Note that the current date is always used; it’s not just a default value that you can override. So even if you set a value for this field when creating the object, it will be ignored. If you want to be able to modify this field, set the following instead of auto_now_add=True:For DateTimeField: default=datetime.now – from datetime.now()For DateTimeField: default=timezone.now – from django.utils.timezone.now()
Automatically set the field to now when the object is first created. Useful for creation of timestamps. Note that the current date is always used; it’s not just a default value that you can override. So even if you set a value for this field when creating the object, it will be ignored. If you want to be able to modify this field, set the following instead of auto_now_add=True:
For DateTimeField: default=datetime.now – from datetime.now()
For DateTimeField: default=timezone.now – from django.utils.timezone.now()
Note: The options auto_now_add, auto_now, and default are mutually exclusive. Any combination of these options will result in an error.
Illustration of DateTimeField using an Example. Consider a project named geeksforgeeks having an app named geeks.
Refer to the following articles to check how to create a project and an app in Django.
How to Create a Basic Project using MVT in Django?
How to Create an App in Django ?
Enter the following code into models.py file of geeks app.
from django.db import modelsfrom django.db.models import Model# Create your models here.  class GeeksModel(Model):    geeks_field = models.DateTimeField()
Add the geeks app to INSTALLED_APPS
# Application definition  INSTALLED_APPS = [    'django.contrib.admin',    'django.contrib.auth',    'django.contrib.contenttypes',    'django.contrib.sessions',    'django.contrib.messages',    'django.contrib.staticfiles',    'geeks',]
Now when we run makemigrations command from the terminal,
Python manage.py makemigrations
A new folder named migrations would be created in geeks directory with a file named 0001_initial.py
# Generated by Django 2.2.5 on 2019-09-25 06:00  from django.db import migrations, models  class Migration(migrations.Migration):      initial = True      dependencies = [    ]      operations = [        migrations.CreateModel(            name ='GeeksModel',            fields =[                ('id',                   models.AutoField(                  auto_created = True,                  primary_key = True,                  serialize = False,                   verbose_name ='ID'                )),                ('geeks_field', models.DateTimeField()),            ],        ),    ]
Now run,
Python manage.py migrate
Thus, an geeks_field DateTimeField is created when you run migrations on the project. It is a field to store datetime.datetime python object.
DateTimeField is used for storing python datetime.datetime instance in the database. One can store any type of date and time using the same in the database. Let’s try storing a date in model created above.
# importing the model# from geeks appfrom geeks.models import GeeksModel  # importing datetime moduleimport datetime  # creating an instance of # datetime.dated = datetime(2015, 10, 09, 23, 55, 59, 342380)  # creating an instance of # GeeksModelgeek_object = GeeksModel.objects.create(geeks_field = d)geek_object.save()
Now let’s check it in admin server. We have created an instance of GeeksModel.
Field Options are the arguments given to each field for applying some constraint or imparting a particular characteristic to a particular Field. For example, adding an argument null = True to DateTimeField will enable it to store empty values for that table in relational database.Here are the field options and attributes that an DateTimeField can use.
NaveenArora
Django-models
Python Django
Python
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