sql - How can I model the following scenario using a single primary key instead of a compound primary key? -

suppose modelling athletics event. primary key date, track , race_no.

class event(models.model):     date = models.datefield()     race_no = models.integerfield()          track = models.charfield(max_length = 4)     temperature = models.integerfield()  class race(models.model):     date = models.datefield()     race_no = models.integerfield()          track = models.charfield(max_length = 4)     athlete_id = models.foreignkey(athlete)     finishing_pos = models.integerfield()    

now suppose wish provide form users particular event. input date, race_no , track. in results wish provide event results along temperature. trivial sql joins. django @ moment not have lot of support compound keys. how can model use case single auto incrementing primary key, more django friendly.

use unique_together. way can have incrementing ids on when put form unique key.

you define unique_together in class' meta class.

class race(models.model):     date = models.datefield()     race_no = models.integerfield()          track = models.charfield(max_length = 4)     athlete_id = models.foreignkey(athlete)     finishing_pos = models.integerfield()      class meta:         unique_together = ("date", "race_no", "track")