make QuerySet.exclude() range lookup exclude data with a null boundary

[WaVEV]

No description provided.

[timgraham]

I wonder about the behavior when an endpoint is null. Example:

queryset = SimulationRun.objects.filter(
    midpoint__range=[F("start__time"), None]
)
self.assertSequenceEqual(queryset, [])

On SQLite and PostgreSQL, the SQL WHERE "midpoint" BETWEEN "time" AND NULL returns no results.

With this patch, MongoDB returns [s1, s2].

But I'm not sure if this is a valid use case since Django doesn't document or test it. And actually, MongoDB's results seem reasonable if you interpret range=[F("start__time"), None] as meaning "give me values from the start time to the end of all time".

[WaVEV]

I wonder about the behavior when an endpoint is null. Example:

queryset = SimulationRun.objects.filter(
    midpoint__range=[F("start__time"), None]
)
self.assertSequenceEqual(queryset, [])

On SQLite and PostgreSQL, the SQL WHERE "midpoint" BETWEEN "time" AND NULL returns no results.

With this patch, MongoDB returns [s1, s2].

But I'm not sure if this is a valid use case since Django doesn't document or test it. And actually, MongoDB's results seem reasonable if you interpret range=[F("start__time"), None] as meaning "give me values from the start time to the end of all time".

Well, I misunderstood it. I thought that None allows us to get values from the start time to the end of all time.

[timgraham]

It might be fine. I found that at least for Microsoft's SQL: "If any input to the BETWEEN or NOT BETWEEN predicate is NULL, the result is UNKNOWN."

[WaVEV]

It might be fine. I found that at least for Microsoft's SQL: "If any input to the BETWEEN or NOT BETWEEN predicate is NULL, the result is UNKNOWN."

"While it is a valid definition, the issue is in how we handle Null or None values. I don't believe this change fixes the test I mean the functionality.

[timgraham]

What I mean is that I'm not sure we have to match the behavior on SQLite/PostgreSQL, since the expected result isn't well-defined by the SQL standard.