#31312: Wrong MySQL query generation after version 3.0.3.
-------------------------------------+-------------------------------------
Reporter: | Owner: nobody
rick2ricks |
Type: Bug | Status: new
Component: Database | Version: 3.0
layer (models, ORM) | Keywords: mysql ORM
Severity: Normal | DateTimeField DurationField
Triage Stage: | Has patch: 0
Unreviewed |
Needs documentation: 0 | Needs tests: 0
Patch needs improvement: 0 | Easy pickings: 0
UI/UX: 0 |
-------------------------------------+-------------------------------------
After updating from 3.0.2 to 3.0.3, Django is generating a wrong MySQL
query for the queryset method ''with_duration'' in the following example:
{{{
#!python
#models.py:
from datetime import datetime
import pytz
from django.db import models
from django.db.models.functions import Cast
class PhaseQueryset(models.QuerySet):
def with_duration(self,):
base_date = datetime(2000, 1, 3, 0, tzinfo=pytz.utc)
# When I use base_date to do the end_total_time math in 3.0.3
together
# with ended_at annotated, it creates a wrong query
qs = self.annotate(
ended_at=models.Case(
models.When(
models.Q(type='TYPEONE'),
then=models.functions.Now()
),
default=models.F('started_at'),
output_field=models.DateTimeField(),
),
base_date=models.functions.Cast(
models.Value(base_date),
output_field=models.DateTimeField()
),
end_total_time=models.ExpressionWrapper(
models.F('ended_at') - models.F('base_date'),
output_field=models.fields.DurationField()
)
)
print(qs.values('end_total_time').query)
return qs
# Create your models here.
class Phase(models.Model):
objects = PhaseQueryset().as_manager()
started_at = models.DateTimeField()
type = models.CharField(max_length=40)
}}}
== Result query on 3.0.3:
{{{
SELECT TIMESTAMPDIFF(MICROSECOND, CAST(TYPEONE AS datetime(6)),
CASE WHEN `daterror_phase`.`type` = 2000-01-03 00:00:00+00:00
THEN CURRENT_TIMESTAMP
ELSE `daterror_phase`.`started_at` END) AS `end_total_time`
FROM `daterror_phase`
}}}
== Result query on 3.0.2:
{{{
SELECT TIMESTAMPDIFF(MICROSECOND, CAST(2000-01-03 00:00:00+00:00 AS
datetime(6)),
CASE WHEN `daterror_phase`.`type` = TYPEONE
THEN CURRENT_TIMESTAMP
ELSE `daterror_phase`.`started_at` END) AS `end_total_time`
FROM `daterror_phase`
}}}
--
Ticket URL: <https://code.djangoproject.com/ticket/31312>
Django <https://code.djangoproject.com/>
The Web framework for perfectionists with deadlines.
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