django多保存数据

django多保存数据

Saving ForeignKey and ManyToManyField fields

Updating a ForeignKey field works exactly the same way as saving a normal field -- simply assign an object of the right type to the field in question. This example updates the blog attribute of an Entry instance entry:

>>> from blog.models import Entry>>> entry = Entry.objects.get(pk=1)>>> cheese_blog = Blog.objects.get(name="Cheddar Talk")>>> entry.blog = cheese_blog>>> entry.save()

Updating a ManyToManyField works a little differently -- use the add() method on the field to add a record to the relation. This example adds the Author instance joe to the entry object:

>>> from blog.models import Author>>> joe = Author.objects.create(name="Joe")>>> entry.authors.add(joe)

To add multiple records to a ManyToManyField in one go, include multiple arguments in the call to add(), like this:

>>> john = Author.objects.create(name="John")>>> paul = Author.objects.create(name="Paul")>>> george = Author.objects.create(name="George")>>> ringo = Author.objects.create(name="Ringo")>>> entry.authors.add(john, paul, george, ringo)