Django query, greater than and lower than are not working

Question

I have the following table:

class OverallAdvise(mixins.OrdMixin, mixins.EqMixin, models.Model):
    section = models.ForeignKey('quest.Section',
                                on_delete=models.CASCADE,
                                related_name='section_owner')
    range_start = models.IntegerField(blank=True, null=True)
    range_end = models.IntegerField(blank=True, null=True)
    get_advise = models.CharField(max_length=500)

Then, in serializer I'm trying to select the get_advise based on a calculated score.

My query is:

get_overall_advise = OverallAdvise.objects.filter(section_id = section_id, range_start__gte = section_overall_score, range_end__lte = section_overall_score).values("get_advise")

but it's not working.

When I use only section_id in my query, it's working.

section_id=6 and section_overall_score=8 are given.

I need something like range_start<=6<=range_end .

This is an instance of my mysql table:

Can you help me please?

Answer 1

In your mysql example, I see that range_start is never greater than range_end, so range_start__gte=value and range_end__lte=value won't match any entry since value is the same. Except maybe range_start == range_end == value

So if you want range_start <= 6 <= range_end you should use range_start__lte=6, range_end__gte=6

Answer 2

When writing you ORM query as if statements you will see the error

for row in OverallAdvise.objects.all():
    if row.section_id == section_id:
        if range_start >= section_overall_score:
            if range_end <= section_overall_score:
                return row.get_advice

This will never be successful as range_start <= range_end . I think you wanted to switch lte and gte around in your query.

get_overall_advise = OverallAdvise.objects.filter(section_id = section_id, range_start__lte = section_overall_score, range_end__gte = section_overall_score).values("get_advise")