DJANGO: ValidationError ["'journals__Start_Date' value has an invalid date format. It must be in YYYY-MM-DD format."]

Question

I dont know what I am doing wrong in my code

I want to perform this:

 journal.objects.filter(Q(User=request.user) | Q(Date__range=[('journals__Start_Date'),('journals__End_Date')])

My models.py look like this:

class journal(models.Model):
    User = models.ForeignKey(settings.AUTH_USER_MODEL,on_delete=models.CASCADE,null=True,blank=True)
    Company = models.ForeignKey(company,on_delete=models.CASCADE,null=True,blank=True,related_name='Companyname')
    Date = models.DateField()
    By = models.ForeignKey(ledger1,on_delete=models.CASCADE,related_name='Debitledgers')
    To = models.ForeignKey(ledger1,on_delete=models.CASCADE,related_name='Creditledgers')
    Debit = models.DecimalField(max_digits=10,decimal_places=2)
    Credit = models.DecimalField(max_digits=10,decimal_places=2)

class selectdatefield(models.Model):
    Journal = models.ForeignKey(journal,on_delete=models.CASCADE,null=True,blank=True,related_name='journals')
    Start_Date = models.DateField(blank=True, null=True)
    End_Date = models.DateField(blank=True, null=True)

Do anyone have any idea what is wrong in my code?

I have used F expressions but it doesnt filter the date range...

From where do you get journals__Start_Date -> value and the next one? — Rarblack, Oct 10 '18 at 10:36
'journals' is the related name of the foreign key reference in selectdatefield model — Niladry Kar, Oct 10 '18 at 10:37
I understand but you have to give value to Q in order to search — Rarblack, Oct 10 '18 at 10:38
You forgot the `F`s, now you have a string, not a field reference.. — Willem Van Onsem, Oct 10 '18 at 10:39
No I dont want to search...I just want to filter the Date in journal between Start_Date and End_Date of selectdatefield model...Through a reverse relation — Niladry Kar, Oct 10 '18 at 10:40
the values for Date_range need to be formatted date strings, like: Sample.objects.filter(date__range=["2011-01-01", "2011-01-31"]) so you need to get those dates and pass them in... — Hoff, Oct 10 '18 at 10:40
also see https://stackoverflow.com/questions/4668619/django-database-query-how-to-filter-objects-by-date-range — Hoff, Oct 10 '18 at 10:41
@NiladryKar: that is exactly what `F`s do: they refer to a field, not per se a field of that model, it can use reverse relations as well. — Willem Van Onsem, Oct 10 '18 at 10:42
Yeah I know that,...But when I am using F expressions its not filtering it in the right way — Niladry Kar, Oct 10 '18 at 10:46
@NiladryKar: that is likely because there are two or more `selectdatefield`s for one `journal`, or no `selectdatefield` at all. — Willem Van Onsem, Oct 10 '18 at 10:47
The problem is you are not passing any data. You should get the user from request so that Q can find the dates related to this user. — Rarblack, Oct 10 '18 at 10:47

score 1 · Accepted Answer · answered Oct 10 '18 at 10:52

You can not pass a 2-tuple of F-objects to the __range lookup. It works in the sense that wit will write a query like:

-- ...
WHERE date BETWEEN F(column1) AND F(column2)

So it takes the str(..) of the F() object, which is not how the F objects should be translated.

But this of course makes no sense. That being said, a __range can be emulted with an __gte and an __lte:

journal.objects.filter(
    Q(User=request.user) |
    Q(Date__gte=F('journals__Start_Date'), Date__lte=F('journals__End_Date'))
)

DJANGO: ValidationError ["'journals__Start_Date' value has an invalid date format. It must be in YYYY-MM-DD format."]

1 Answers1