What is the related_name
argument useful for on ManyToManyField
and ForeignKey
fields? For example, given the following code, what is
prefetch_related
use for prefetch data for Many to many and many to one relationship data.
select_related
is to select data from a single value relationship. Both of these are used to fetch data from their relationships from a model. For example, you build a model and a model that has a relationship with other models. When a request comes you will also query for their relationship data and Django has very good mechanisms To access data from their relationship like book.author.name
but when you iterate a list of models for fetching their relationship data Django create each request for every single relationship data. To overcome this we do have prefetchd_related
and selected_related