Hej! 
I have 5 models which are connected hierarchical with each other.
Section → division → group → class → wz
one section can have multiple divisions, but one division can only have one section (and so on). Therefor I have ForeignKeys set:
# models.py
class NaceSection(models.Model):
code = models.CharField(max_length=1, unique=True)
description_english = models.CharField(max_length=500)
class NaceDivision(models.Model):
code = models.CharField(max_length=2, unique=True)
nace_section = models.ForeignKey(NaceSection, on_delete=models.CASCADE, related_name="nace_section")
description_english = models.CharField(max_length=500)
class NaceGroup(models.Model):
nace_division = models.ForeignKey(NaceDivision, on_delete=models.CASCADE, related_name="nace_division")
code = models.CharField(max_length=4, unique=True)
description_english = models.CharField(max_length=500)
class NaceClass(models.Model):
nace_group = models.ForeignKey(NaceGroup, on_delete=models.CASCADE, related_name="nace_group")
code = models.CharField(max_length=5, unique=True)
description_english = models.CharField(max_length=500)
class WZ(models.Model):
nace_class = models.ForeignKey(NaceClass, on_delete=models.PROTECT, related_name="wz")
code = models.CharField(max_length=7, unique=True)
description_english = models.CharField(max_length=500)
I than have a model where all those are integrated as M2M fields with a dropdown option.
My goal is to only get the divisions which are in the already selected section in the admin area. (and so on)
I tried smart-select ChainedForeignKey:
# models.py
class Institution(models.Model):
nace_sections = models.ManyToManyField(
NaceSection,
related_name="nace_sections"
)
nace_divisions = ChainedForeignKey(
NaceDivision,
chained_field="nace_sections",
chained_model_field='nace_sections',
blank=True,
)
nace_group = ChainedForeignKey(
NaceGroup,
chained_field="nace_divisions",
chained_model_field='nace_divisions',
blank=True,
)
The organisation and dropdown in the admin area do not change at all and my view with a table of all my results tells me ('42S22', "[42S22] [Microsoft][ODBC Driver 17 for SQL Server][SQL Server]Invalid column name 'nace_divisions_id'. (207) (SQLExecDirectW)")
With the ChainedManyToManyField nothing at all happens. Does anybody know what’s going wrong?
Any help appreciated!
