How can I join two child tables using Django Querset API?

Question

I have a model with two child tables and one parent table. Here is the sample model classes.

# Stores list of unique category names
class Category(models.Model):
    category = models.CharField(max_length=20, unique=True, validators=[MinLengthValidator(limit_value=5)])
    name = models.CharField(max_length=20, validators=[MinLengthValidator(limit_value=8)])

# Parent class for the next two child classes
class DailyLog(models.Model):
    category = models.ForeignKey(Category, on_delete=models.CASCADE)
    name = models.CharField(max_length=100, validators=[MinLengthValidator(limit_value=8)])
    code = models.CharField(max_length=4, validators=[MinLengthValidator(limit_value=3)])
    suggested_values = models.CharField(max_length=100, null=True, blank=True)

# First child class defines display order for dailylog items
class DailyLogDisplayOrder(models.Model):
    category_item = models.ForeignKey(DailyLog, on_delete=models.CASCADE)
    display_order = models.PositiveIntegerField()

# Second Child class publishes dailylog on a daily bases
class DailyLogCheckList(models.Model):
    daily_task = models.ForeignKey(DailyLog, on_delete=models.CASCADE)
    publish_date = models.DateField(auto_now=True)

    daily_task = DailyTaskCategoryManager() # Log manager to get records per category

How do I perform a cartesian product query? The last column comes from the first child table Dailylogdisplayorder. Here is the raw sql.

select daily_task_id, checklist.publish_date, disporder.display_order
from dailylogchecklist checklist, compliance_dailylogdisplayorder disporder
where checklist.daily_task_id = disporder.category_item_id and checklist.publish_date='2020-07-12'

I have tried using cursor.execute() method per Django documentation. However, I am not able to figure out how to return results in QuyerySet. And also looking for a better way to combine child columns using QuerySet. The return queryset is assigned to a formset.

class DailyTaskCategoryManager(models.Manager):
def with_displayorder(self, user):
     from django.db import connection
     dtrange = datetime.today().date()
     with connection.cursor() as cursor:
     cursor.execute("select daily_task_id, checklist.publish_date, disporder.display_order
                     from dailylogchecklist checklist, compliance_dailylogdisplayorder disporder
                     where checklist.daily_task_id = disporder.category_item_id and 
                     checklist.publish_date=%s", [dtrange])
            result_list = []
            for row in cursor.fetchall():
                p = self.model(id=row[0], daily_task_id=row[1], publish_date=row[2])
                p.display_order = row[3]
                result_list.append(p)
            return result_list

Answer 1

I already answered to a similar question, You can use prefetch_related() to get the related child table data. Check this answer

https://stackoverflow.com/a/71571509/9561654