Annotate and Subquery with 2 tables in 2 different databases

[Mạnh ĐỖ]

I want to use annotate and subquery to join tables.

Table1 in database1 and table2 in database2. But it's not work.

I got the error:

 QuerySet.annotate() received non-expression(s): database1.

the code here:

from django.db.models import Subquery, OuterRef, Count from app1.models import Table1 from app2.models import Table2 subquery = Table2.objects.filter(table1_id=OuterRef('id')).values('table1_id').annotate(count=Count('id')).values('count') queryset = Table1.objects.annotate(table2_count=Subquery(subquery, output_field=models.IntegerField()), using='database1')

Could anyone help me?

[Jason]

this won't work, you're doing things across two entire dbs.  So you'l have to implement all the logic in python to execute.