Updating FilesField() django with S3 - django

Question

I want to update the FileField with new file. All the files are saved on S3.
models.py
class PrescriptionMediaStorage(S3Boto3Storage):
location = settings.AWS_PRESCRIPTION_MEDIA_LOCATION
file_overwrite = True
custom_domain = f'{settings.AWS_STORAGE_BUCKET_NAME}.s3.amazonaws.com'
class UploadPrescription(models.Model):
image = models.FileField(storage=PrescriptionMediaStorage())
For createview i used:
prescription_obj = UploadPrescription.objects.create(image=image)
prescription_obj.image = prescription_obj.image.url
prescription_obj.save()
For Updateview i tried this but it's giving error
UploadPrescription.objects.filter(id=prescription_id).update(image=image)
prescription_obj = UploadPrescription.objects.get(id=prescription_id)
prescription_obj.image = prescription_obj.image.url
prescription_obj.save()
when i tried to open the saved url in image field i got below message
<Error>
<Code>NoSuchKey</Code>
<Message>The specified key does not exist.</Message>
<Key>media/prescription/1STUSERS-BANNER.jpg</Key>
<RequestId>5D1396D45DF8E1F7</RequestId>
<HostId>0Chq0gedgy/o8942zo5JEz2Tp4iE6df51v0o5iY6GnNGKH3bOXb1ee9XKupKY5GYCfvankTGXHI=
</HostId>
</Error>

Answer 1

Okay, not sure what you are doing here, buth this is how to properly use an ImageField - try these changes and see if they resolve your issue:
Don't write a url to the image field of your model. Assuming <the_image_file> is a valid image file, all you need is one line:
views.py
# creates and saves an UploadPresecription with the given image:
prescription_obj = UploadPrescription.objects.create(image=<the_image_file>)
To use the image in an <image> div, you can access the url like so:
template.html
<image src="{{prescription_obj.image.url}}" />
To replace the image on the prescription_obj, you can simply do this:
views.py
prescription_obj = UploadPrescription.objects.get(id=<the_id>)
prescription_obj.image = <the_new_image_file>
prescription_obj.save()
Note, depending on your settings, your S3 bucket may retain a version of the old image but it will no longer be associated with the updated prescription_obj.
Read about the ImageField here:
https://docs.djangoproject.com/en/3.1/topics/files/