CODEWITHSUNDEEP
pythondjangodjango-modelsorm
Nahidujjaman Hridoy
Nahidujjaman Hridoy

Reputation: 2247

How to get query list that does not exist in another model in Django ORM?

I have three table:

Table1

class Table1(models.Model):
    field1 = model.CharField(...)
    field2 = model.CharField(...)

Table2

class Table2(models.Model):
    field1 = model.CharField(...)
    field2 = model.CharField(...)

Table3

class Table3(models.Model):
    table1 = model.ForeignKey(Table1)
    table2 = model.ForeignKey(Table2)

I want to get all Table1 data that does not exists in Table3 with a which also includes Table2.

For Example: In Table1 I have three rows: rows1, rows2, rows3

In Table2 I have One rows: r1

In Table3 I have One rows: table1 = rows1 table2 = r1

I want to get rows2 and rows3 from Table1 when I am searching against Table2s r1 in Table3

I can get my expected result using this code:

table3 = Table3.objects.filter(table2=Table2.objects.get(id=1)).values_list('table1')
queryset = Table1.objects.filter(~Q(id__in=table3 ))

My Question now is there any better way to do this?

Thanks

Upvotes: 2

Views: 871

Answers (1)

willeM_ Van Onsem
willeM_ Van Onsem

Reputation: 477513

You can work with .exclude(…) [Django-doc]:

Table1.objects.exclude(table3__table2_id=1)

Upvotes: 1

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