5. Copy TO / FROM support

For database engines (i.e., Postgres) that support copying data into and out of a buffer Django-bulkmodel exposes this functionality into the queryset.

There are now two methods you can call:

• copy_from_objects: writes data from the provided list of objects to the database.
• copy_to_instances: reads data out of a buffer and populates a list of objects

5.1. Examples

Suppose you have the following model:

from bulkmodel.models import BulkModel

class Foo(BulkModel):
    name = models.CharField(max_length=50, blank=False)
    value = models.IntegerField(null=False)

Populate it with some data and use copy_from_objects to write the data into the database:

ls = []
for i in range(1000):
    ls.append(Foo(
        name = random_str(),
        value = randint(0, 1000),
    ))

# returning the queryset is optional
foos = Foo.objects.copy_from_objects(ls, return_queryset=True)

Likewise you can fetch data out the database by populating a list of objects from a buffer:

objs = Foo.objects.copy_to_instances()