How to assign every PointField with latitude and longitude in update() using F expression?

manpreet Best Answer 2 years ago

so I am writing migration which will assign latitude and longitude values">values to PointField in every record of database.

I have one solution which works but it is too slow for a 10 000 000 records of database. So I can update every record in for loop by simply assigning lat and long to a point and then save a record. But I wanted to use Django's .update() method to do this much faster.

class Listing(AirbnbModel):
 latitude = models.DecimalField()
 longitude = models.DecimalField()
 point = PointField(srid=4326, geography=True, null=True) # new field

This works but takes too much time and it is almost impossible to do this for 10 000 000 records

for listing in Listing.objects.all():
        listing.point = Point(float(listing.latitude), float(listing.longitude))
        listing.save()

Here is what I tried to do but I got an error.

    Listing.objects.all().update(point=ExpressionWrapper(F('latitude'), F('longitude') , output_field=PointField()))

I tried this as well

      Listing.objects.all().update(point=ExpressionWrapper(Point(Value('latitude'), Value('longitude')), output_field=PointField()))

But this does not work at all.