`select_related` and `prefetch_related`

When I inspected the actual SQL queries being run against DB, I found that for foreignkey and manytomany relationships, we have the n+1 problem.

For example, suppose there are 5 teams, each with 11 members, this query:

query {
  teams {
    edges {
      node {
        members {
          edges {
            node {
              name
            }
          }
        }
      }
    }
  }
}

will result in 1 query for selecting teams, and 5 more queries for selecting members of each team. 6 queries in total.

Normally, we would do a query like this Team.objects.all().prefetch_related('members') to reduce to 2 queries.

I think it would be extremely beneficial if DjangoObjectType can detect special fields:

• ForeignField
• OneToOneField
• OneToManyField
• ManyToManyField and apply appropriate prefetch_related and/or select_related when such fields are present in graph queries.