How to calculate daily average in django serializer
my model :
class Record(models.Model):
type = models.CharField(max_length=9, choices=RECORD_CHOICES)
user = models.ForeignKey(User,on_delete=models.CASCADE)
record = models.DecimalField(decimal_places=4,max_digits=8)
date_time = models.DateTimeField()
my serializer:
class RecordSerializer_1(serializers.ModelSerializer):
class Meta:
model = Record
fields = ['type','record','date_time']
my view :
records = Record.objects.filter(user=user,type="HeartRate")
serializer = RecordSerializer_1(records, many=True)
I have more than one record at same day , I need to calculate average and return only one record per day
Comments:
2023-01-23 00:55:04
So you want to calculate an average over records on the same day, but what record will you return? The resulting average might be a decimal which is not a record.
Answers(1) :
To get the average of a record given datetime:
from django.db.models import Avg
# Ex records:
records = [2, 3, 4, 7, 9]
day = datetime.datetime.now()
agg = Record.objects.filter(date_time=day).aggregate(record_average=Avg("record"))
# {'record_average': Decimal('5')}
You can have a look at the Django documentation for more about aggregation.