Date comparison lookup operators

[vbmendes]

It would be nice to have lookup operators such as day_gt , day_gte , day_lt , day_lte , month_gt , month_gte , month_lt and month_lte . With this, we will be able to do comparisons such as date__month_gt=6 to find objects with the date object in the second semester, and much more good things. The lookups are:

• day_lt -- day lower then;
• day_gt -- day greather then;
• day_lte -- day lower then or equal;
• day_gte -- day greather then or equal;
• day_range -- accepts a tuple or list with two elements, just like the range loopup operator;

And the same thing for month, year and week_day.

[Alex Gaynor]

Please use preview.

[David Danier <goliath.mailinglist@…>]

What about day/week/....in? :)

[anonymous]

+1

[anonymous]

dont forget year

[anonymous]

in statement will be great too

[fas]

Soemthing for "older than 6 months" etc. would be great too.

[David Danier <goliath.mailinglist@…>]

Replying to fas:

Soemthing for "older than 6 months" etc. would be great too.

That's already possible:

 Foo.objects.filter(datetime__lte=six_month_ago)

[Ulrich Petri]

Related: #16187 Refactor of the lookup system

[ANUBHAV JOSHI]

Is anyone working on this or has worked in the past?
Or have been there any changes in the django version which support this.

[Anssi Kääriäinen]

These will be trivial to implement once #16187 lands.

For example month_gte could be written as:

from django.db.models import Lookup

class MonthGte(Lookup):
    lookup_name = 'month_gte'

    def as_sql(self, qn, connection):
        lhs, lhs_params = self.process_lhs(qn, connection)
        rhs, rhs_params = self.process_rhs(qn, connection)
        return 'EXTRACT(month FROM %s) >= %s' % (lhs, rhs), lhs_params + rhs_params
DateField.register_lookup(MonthGte)

Or, even better way is to write a MonthExtract:

from django.db.models import Extract

class MonthExtract(Extract):
    lookup_name = 'month'
    output_type = IntegerField()

    def as_sql(self, qn, connection):
        lhs, lhs_params = qn.compile(self.lhs)
        return 'EXTRACT(month FROM %s) % lhs, lhs_params
DateField.register_lookup(MonthExtract)

Using the first one implements .filter(datefield__month_gte=6) but the second way implements any lookup on month, for example both .filter(datefield__month__gte=6) and .filter(datefield__month__lte=6) will just work.

[Aymeric Augustin]

I don't think we want to provide lookups for all the permutations of (DateField, DateTimeField, TimeField) x (year, month, day, dow, doy, hour, minute, second, microsecond) x (eq, ne, gt, lt, gte, lte). So the solution given by Anssi is the way to go.