[Django] #31839: Add additional database functions.
Django
-------------------------------------+-------------------------------------
Reporter: Nick Pope | Owner: Nick Pope
Type: New | Status: assigned
feature |
Component: Database | Version: master
layer (models, ORM) | Keywords: functions, random,
Severity: Normal | truncate, log2, log10, bit length,
Triage Stage: | octet length, hyperbolic
Unreviewed | Has patch: 0
Needs documentation: 0 | Needs tests: 0
Patch needs improvement: 0 | Easy pickings: 0
UI/UX: 0 |
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I propose adding some additional database functions:
- `Random` -- generate random numbers in the range `[0.0, 0.1)`.
- `Truncate` -- round number towards zero. (SQL function is `TRUNC`, but
`Trunc` is used for date truncation in Django.)
- `Log2` and `Log10` -- simple logarithm functions without needing to
provide the base.
- `ACosh`, `ASinh`, `ATanh`, `Cosh`, `Sinh`, and `Tanh` -- hyperbolic
functions.
- `BitLength` and `OctetLength` -- length of string in bits and bytes,
complement to `Length` which is character length.
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Ticket URL: <https://code.djangoproject.com/ticket/31839>
Django <https://code.djangoproject.com/>
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Django
-------------------------------------+-------------------------------------
Reporter: Nick Pope | Owner: Nick Pope
Component: Database layer | Version: master
(models, ORM) |
Severity: Normal | Resolution:
Keywords: functions, random, | Triage Stage:
truncate, log2, log10, bit | Unreviewed
length, octet length, hyperbolic |
Has patch: 1 | Needs documentation: 0
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 0 | UI/UX: 0
-------------------------------------+-------------------------------------
* has_patch: 0 => 1
Comment:
[https://github.com/django/django/pull/13252 PR]
--
Ticket URL: <https://code.djangoproject.com/ticket/31839#comment:1>
Django
-------------------------------------+-------------------------------------
Reporter: Nick Pope | Owner: Nick Pope
Component: Database layer | Version: master
(models, ORM) |
Severity: Normal | Resolution:
Keywords: functions, random, | Triage Stage:
truncate, log2, log10, bit | Unreviewed
length, octet length, hyperbolic |
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 0 | UI/UX: 0
-------------------------------------+-------------------------------------
Comment (by felixxm):
I'm not sure if it's worth adding extra database functions:
- `Log2` and `Log10` can be achieved with proving base to `Log` so I'm
against them,
- hyperbolic functions are supported only on PostgreSQL 12+, we need to
emulate them on other DBs, it's not worth, IMO,
- `BitLength` and `OctetLength` will probably not work on Oracle.
`Truncate` and `Round` sound reasonable.
--
Ticket URL: <https://code.djangoproject.com/ticket/31839#comment:2>
Django
-------------------------------------+-------------------------------------
Reporter: Nick Pope | Owner: Nick Pope
Component: Database layer | Version: master
(models, ORM) |
Severity: Normal | Resolution:
Keywords: functions, random, | Triage Stage:
truncate, log2, log10, bit | Unreviewed
length, octet length, hyperbolic |
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 0 | UI/UX: 0
-------------------------------------+-------------------------------------
Old description:
> I propose adding some additional database functions:
>
> - `Random` -- generate random numbers in the range `[0.0, 0.1)`.
> - `Truncate` -- round number towards zero. (SQL function is `TRUNC`, but
> `Trunc` is used for date truncation in Django.)
> - `Log2` and `Log10` -- simple logarithm functions without needing to
> provide the base.
> - `ACosh`, `ASinh`, `ATanh`, `Cosh`, `Sinh`, and `Tanh` -- hyperbolic
> functions.
> - `BitLength` and `OctetLength` -- length of string in bits and bytes,
> complement to `Length` which is character length.
New description:
I propose adding some additional database functions:
- `Random` -- generate random numbers in the range `[0.0, 0.1)`.
- `Truncate` -- round number towards zero. (SQL function is `TRUNC`, but
`Trunc` is used for date truncation in Django.)
- `Log2` and `Log10` -- simple logarithm functions without needing to
provide the base.
- `ACosh`, `ASinh`, `ATanh`, `Cosh`, `Sinh`, and `Tanh` -- hyperbolic
functions.
- `BitLength` and `ByteLength` -- length of string in bits and bytes,
complement to `Length` which is character length.
--
--
Ticket URL: <https://code.djangoproject.com/ticket/31839#comment:3>
Django
-------------------------------------+-------------------------------------
Reporter: Nick Pope | Owner: Nick Pope
Component: Database layer | Version: master
(models, ORM) |
Keywords: functions, random, | Triage Stage:
truncate, log2, log10, bit | Unreviewed
length, octet length, hyperbolic |
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 0 | UI/UX: 0
-------------------------------------+-------------------------------------
* status: assigned => closed
* resolution: => wontfix
Comment:
I think we need to decide at what point we say enough is enough here, and
recommend users create their own functions like we did with template tags.
For me hyperbolic functions cross that line. You can start a discussion on
DevelopersMailingList if you don't agree. Personally I've never used any
of proposed database functions.
--
Ticket URL: <https://code.djangoproject.com/ticket/31839#comment:4>
Django
-------------------------------------+-------------------------------------
Reporter: Nick Pope | Owner: Nick Pope
Component: Database layer | Version: master
(models, ORM) |
Severity: Normal | Resolution: wontfix
Keywords: functions, random, | Triage Stage:
truncate, log2, log10, bit | Unreviewed
length, octet length, hyperbolic |
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 0 | UI/UX: 0
-------------------------------------+-------------------------------------
Comment (by Nick Pope):
Will you still take `Random` and `Truncate`?
In the case of `Random` there is also a nice bit of simplification:
https://github.com/django/django/commit/c8913d41e74859747893dc21356a1fb6906c56e9
--
Ticket URL: <https://code.djangoproject.com/ticket/31839#comment:5>
Django
-------------------------------------+-------------------------------------
Reporter: Nick Pope | Owner: Nick Pope
Component: Database layer | Version: master
(models, ORM) |
Severity: Normal | Resolution: wontfix
Keywords: functions, random, | Triage Stage:
truncate, log2, log10, bit | Unreviewed
length, octet length, hyperbolic |
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 0 | UI/UX: 0
-------------------------------------+-------------------------------------
Comment (by felixxm):
`Random()` is already there (as an expression) so we can change it to a
function and promote in docs, I'm just not sure why we change its
behavior.
`Truncate()` can be confused with `Trunc()` for dates/datetimes, and we
can achieve the same by using `Cast(..., models.IntegerField())` so I
don't think it's necessary.
--
Ticket URL: <https://code.djangoproject.com/ticket/31839#comment:6>