Django ORM:等同于SQL的NOT IN`exclude和Q对象不起作用

Question

问题

我正在尝试使用Django ORM来执行相当于SQLNOT IN子句的操作，在一个子select中提供一个ID列表，以从日志记录表中带回一组记录。我不知道这是否可能。

型号

class JobLog(models.Model):
job_number = models.BigIntegerField(blank=True, null=True)
name = models.TextField(blank=True, null=True)
username = models.TextField(blank=True, null=True)
event = models.TextField(blank=True, null=True)
time = models.DateTimeField(blank=True, null=True)

我尝试了什么

我的第一次尝试是使用exclude，但这会使NOT否定整个Subquery，而不是所需的NOT IN:

query = (
JobLog.objects.values(
"username", "job_number", "name", "time",
)
.filter(time__gte=start, time__lte=end, event="delivered")
.exclude(
job_number__in=models.Subquery(
JobLog.objects.values_list("job_number", flat=True).filter(
time__gte=start, time__lte=end, event="finished",
)
)
)
)

不幸的是，这会产生这样的SQL:

SELECT "view_job_log"."username", "view_job_log"."group", "view_job_log"."job_number", "view_job_log"."name", "view_job_log"."time"
FROM "view_job_log"
WHERE (
"view_job_log"."event" = 'delivered'
AND "view_job_log"."time" >= '2020-03-12T11:22:28.300590+00:00'::timestamptz
AND "view_job_log"."time" <= '2020-03-13T11:22:28.300600+00:00'::timestamptz
AND NOT (
"view_job_log"."job_number" IN (
SELECT U0."job_number"
FROM "view_job_log" U0
WHERE (
U0."event" = 'finished' AND U0."time" >= '2020-03-12T11:22:28.300590+00:00'::timestamptz
AND U0."time" <= '2020-03-13T11:22:28.300600+00:00'::timestamptz
)
)
AND "view_job_log"."job_number" IS NOT NULL
)
)

我需要的是第三个AND子句是AND "view_job_log"."job_number" NOT IN而不是AND NOT (。

我还尝试过先使用exclude作为自己的查询进行子选择，如下所示：

不在中的SQL的Django等价物

然而，这也产生了同样的问题。然后我尝试了一个Q对象，它产生了一个类似的查询：

query = (
JobLog.objects.values(
"username", "subscriber_code", "job_number", "name", "time",
)
.filter(
~models.Q(job_number__in=models.Subquery(
JobLog.objects.values_list("job_number", flat=True).filter(
time__gte=start, time__lte=end, event="finished",
)
)),
time__gte=start,
time__lte=end,
event="delivered",
)
)

使用Q对象的尝试再次在没有NOT IN:的情况下生成以下SQL

SELECT "view_job_log"."username", "view_job_log"."group", "view_job_log"."job_number", "view_job_log"."name", "view_job_log"."time"
FROM "view_job_log" WHERE (
NOT (
"view_job_log"."job_number" IN (
SELECT U0."job_number"
FROM "view_job_log" U0
WHERE (
U0."event" = 'finished'
AND U0."time" >= '2020-03-12T11:33:28.098653+00:00'::timestamptz
AND U0."time" <= '2020-03-13T11:33:28.098678+00:00'::timestamptz
)
)
AND "view_job_log"."job_number" IS NOT NULL
)
AND "view_job_log"."event" = 'delivered'
AND "view_job_log"."time" >= '2020-03-12T11:33:28.098653+00:00'::timestamptz
AND "view_job_log"."time" <= '2020-03-13T11:33:28.098678+00:00'::timestamptz
)

有没有办法让Django的ORM做一些类似于AND job_number NOT IN (12345, 12346, 12347)的事情？还是我将不得不使用原始SQL来实现这一点？

提前感谢您阅读这整墙的文本问题。显式比隐式好。：(

Answer 1

我认为最简单的方法是定义一个自定义查找，类似于这个或查找中的

from django.db.models.lookups import In as LookupIn
class NotIn(LookupIn):
lookup_name = "notin"
def get_rhs_op(self, connection, rhs):
return "NOT IN %s" % rhs
Field.register_lookup(NotIn)

或

class NotIn(models.Lookup):
lookup_name = "notin"
def as_sql(self, compiler, connection):
lhs, params = self.process_lhs(compiler, connection)
rhs, rhs_params = self.process_rhs(compiler, connection)
params.extend(rhs_params)
return "%s NOT IN %s" % (lhs, rhs), params

然后在查询中使用它：

query = (
JobLog.objects.values(
"username", "job_number", "name", "time",
)
.filter(time__gte=start, time__lte=end, event="delivered")
.filter(
job_number__notin=models.Subquery(
JobLog.objects.values_list("job_number", flat=True).filter(
time__gte=start, time__lte=end, event="finished",
)
)
)
)

这将生成SQL:

SELECT
"people_joblog"."username",
"people_joblog"."job_number",
"people_joblog"."name",
"people_joblog"."time"
FROM
"people_joblog"
WHERE ("people_joblog"."event" = delivered
AND "people_joblog"."time" >= 2020 - 03 - 13 15:24:34.691222 + 00:00
AND "people_joblog"."time" <= 2020 - 03 - 13 15:24:41.678069 + 00:00
AND "people_joblog"."job_number" NOT IN (
SELECT
U0. "job_number"
FROM
"people_joblog" U0
WHERE (U0. "event" = finished
AND U0. "time" >= 2020 - 03 - 13 15:24:34.691222 + 00:00
AND U0. "time" <= 2020 - 03 - 13 15:24:41.678069 + 00:00)))

Answer 2

使用Exists和特殊外壳NULLs可能会获得相同的结果。

.filter(
~Exists(
JobLog.objects.filter(
Q(jobnumber=None) | Q(jobnumber=OuterRef('jobnumber')),
time__gte=start,
time__lte=end,
event='finished',
)
)
)

Answer 3

你能试试这个吗：

JobLog.objects.filter(time__gte=start, time__lte=end, event="delivered").exclude(time__gte=start, event='finished').exclude(time__lte=end, event='finished')