Add more database functions/aggregates.

[omid zarinmahd]

Hi
I have a question regarding DjangoORM implementation :
you know this ORM supports some database functions that are really handy
but there are many functions in databases that Django ORM doesn't support
is there a reason behind this or do you guys have some plans?
some functions that Django ORM doesn't suppport in Postgresql:
cbrt()
div(y numeric, x numeric)
bit_xor()
bool_and()
covar_samp()
stddev_pop()
percentile_cont()
and there are more I just mentioned on database engine there are functions in Mysql that ORM doesn't support

[Mariusz Felisiak]

Most of functions/aggregates mentioned in the ticket description are included in Django:

• bit_xor() -> django.contrib.postgres.aggregates.BitXor,
• bool_and() -> django.contrib.postgres.aggregates.BoolAnd,
• covar_samp() -> django.contrib.postgres.aggregates.CovarPop (with sample=True),
• stddev_pop() -> django.db.models.StdDev.

As far as I'm aware after implementing #28643 we don't want to add more functions to the core unless they are common and supported by all backends. The current thread is to keep Django a core framework, not providing every utility which might be useful. You can write your own function, e.g.

class Cbrt(Transform):
    function = "CBRT"
    lookup_name = "cbrt"