Django ORM：相当于 SQL`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 SQLNOT IN子句的等效操作，在子选择中提供 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。

该模型

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)

我试过的

我的第一次尝试是使用exclude，但这确实NOT否定了整个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，这产生了这个 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条款AND "view_job_log"."job_number" NOT IN而不是AND NOT (.

我也试过先做子选择，因为它是自己的查询，使用exclude, 如下所示：

Django 相当于 SQL not in

然而，这会产生同样有问题的结果。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",
    )
)

对Q对象的这种尝试再次产生以下 SQL，没有NOT IN：

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
)

有什么办法可以让 Django 的 ORM 做一些等同于 的事情AND job_number NOT IN (12345, 12346, 12347)吗？或者我将不得不放弃原始 SQL 来完成这个？

提前感谢您阅读整个文本墙问题。显式优于隐式。:)

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

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)

或者

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

然后在您的查询中使用它：

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)))