Can I use select_related() with ManyToManyField on Django Models?
django, django-models, django-select-related, python
Solution
Django versions 1.4 and above have `prefetch_related` for this purpose.
The `prefetch_related` method is similar to `select_related`, but does not do a database join. Instead, it executes additional database queries and does the joining in Python.
Problem
I have : ``` class Award(models.Model) : name = models.CharField(max_length=100, db_index=True) class Alias(models.Model) : awards = models.ManyToManyField('Award', through='Achiever') class Achiever(models.Model): award = models.ForeignKey(Award) alias = models.ForeignKey(Alias) count = models.IntegerField(default=1) ``` How can I have an `Alias` which has all its `achiever_set` and `awards` prepopulated? ``` >>> db.reset_queries() >>> Alias.objects.filter(id="450867").select_related("achiever_set__award").get().achiever_set.all()[0].award.name u'Perma-Peddle' >>> len(db.connection.queries) 3 >>> db.reset_queries() >>> Alias.objects.filter(id="450867").select_related("awards").get().awards.all()[0].name u'Dwarfageddon (10 player)' >>> len(db.connection.queries) 2 ``` I'm going to need a lot of access to the award that an alias has already gotten (both the intermediate table and the awards themselves). How can I batch all of these?