Django JOIN query without foreign key -

is there way in django write query using orm, not raw sql allows join on table without there being foreign key? looking through documentation appears in order 1 one relationship work there must foreign key present?

in models below want run query join on useractivity.request_url useractivitylink.url.

class useractivity(models.model):     id = models.integerfield(primary_key=true)     last_activity_ip = models.charfield(max_length=45l, blank=true)     last_activity_browser = models.charfield(max_length=255l, blank=true)     last_activity_date = models.datetimefield(auto_now_add=true)     request_url = models.charfield(max_length=255l, blank=true)     session_id = models.charfield(max_length=255l)     users_id = models.integerfield()     class meta:         db_table = 'user_activity'  class useractivitylink(models.model):     id = models.integerfield(primary_key=true)     url = models.charfield(max_length=255l, blank=true)     url_description = models.charfield(max_length=255l, blank=true)     type = models.charfield(max_length=45l, blank=true)     class meta:         db_table = 'user_activity_link' 

the link table has more descriptive translation of given urls in system, needed reporting system generate.

i've tried creating foreign key useractivity.request_url useractivitylink.url fails following error: error 1452: cannot add or update child row: foreign key constraint fails

no, there isn't effective way unfortunately.

the .raw() there exact thing. if lot slower raw sql.

there blogpost here detailing how query.join() point out. it's not best practice.