Problem with ForeignKey. Django migrations

1
votes

I have to define code.Spatial class like primary_key and codels.LScharacteristic codels.PlannedUsing like foreign key. I face this, when i tried migrate: ProgrammingError: ERROR: the id column specified in the foreign key constraint does not exist.

UPD full log: The above exception was the direct cause of the following exception:

Traceback (most recent call last): File "manage.py", line 23, in execute_from_command_line(sys.argv) File "/home/user/MyProjects/forest-venv/lib/python3.5/site-packages/django/core/management/init.py", line 371, in execute_from_command_line utility.execute() File "/home/user/MyProjects/forest-venv/lib/python3.5/site-packages/django/core/management/init.py", line 365, in execute self.fetch_command(subcommand).run_from_argv(self.argv) File "/home/user/MyProjects/forest-venv/lib/python3.5/site-packages/django/core/management/base.py", line 288, in run_from_argv self.execute(*args, **cmd_options) File "/home/user/MyProjects/forest-venv/lib/python3.5/site-packages/django/core/management/base.py", line 335, in execute output = self.handle(*args, **options) File "/home/user/MyProjects/forest-venv/lib/python3.5/site-packages/django/core/management/commands/migrate.py", line 200, in handle fake_initial=fake_initial, File "/home/user/MyProjects/forest-venv/lib/python3.5/site-packages/django/db/migrations/executor.py", line 117, in migrate state = self._migrate_all_forwards(state, plan, full_plan, fake=fake, fake_initial=fake_initial) File "/home/user/MyProjects/forest-venv/lib/python3.5/site-packages/django/db/migrations/executor.py", line 147, in _migrate_all_forwards state = self.apply_migration(state, migration, fake=fake, fake_initial=fake_initial) File "/home/user/MyProjects/forest-venv/lib/python3.5/site-packages/django/db/migrations/executor.py", line 244, in apply_migration state = migration.apply(state, schema_editor) File "/home/user/MyProjects/forest-venv/lib/python3.5/site-packages/django/db/migrations/migration.py", line 122, in apply operation.database_forwards(self.app_label, schema_editor, old_state, project_state) File "/home/user/MyProjects/forest-venv/lib/python3.5/site-packages/django/db/migrations/operations/fields.py", line 216, in database_forwards schema_editor.alter_field(from_model, from_field, to_field) File "/home/user/MyProjects/forest-venv/lib/python3.5/site-packages/django/db/backends/base/schema.py", line 525, in alter_field old_db_params, new_db_params, strict) File "/home/user/MyProjects/forest-venv/lib/python3.5/site-packages/django/db/backends/postgresql/schema.py", line 122, in _alter_field new_db_params, strict, File "/home/user/MyProjects/forest-venv/lib/python3.5/site-packages/django/db/backends/base/schema.py", line 750, in _alter_field self.execute(self._create_fk_sql(model, new_field, "fk%(to_table)s_%(to_column)s")) File "/home/user/MyProjects/forest-venv/lib/python3.5/site-packages/django/db/backends/base/schema.py", line 133, in execute cursor.execute(sql, params) File "/home/user/MyProjects/forest-venv/lib/python3.5/site-packages/django/db/backends/utils.py", line 100, in execute return super().execute(sql, params) File "/home/user/MyProjects/forest-venv/lib/python3.5/site-packages/django/db/backends/utils.py", line 68, in execute return self._execute_with_wrappers(sql, params, many=False, executor=self._execute) File "/home/user/MyProjects/forest-venv/lib/python3.5/site-packages/django/db/backends/utils.py", line 77, in _execute_with_wrappers return executor(sql, params, many, context) File "/home/user/MyProjects/forest-venv/lib/python3.5/site-packages/django/db/backends/utils.py", line 85, in _execute return self.cursor.execute(sql, params) File "/home/user/MyProjects/forest-venv/lib/python3.5/site-packages/django/db/utils.py", line 89, in exit raise dj_exc_value.with_traceback(traceback) from exc_value File "/home/user/MyProjects/forest-venv/lib/python3.5/site-packages/django/db/backends/utils.py", line 85, in _execute return self.cursor.execute(sql, params)

but I havn't a id column in my model:

from django.db import models
from django.utils.translation import ugettext_lazy as _
from renter.models import RefAbstract, Renter
from django.contrib.gis.db import models
from textwrap import shorten


class Unitt(RefAbstract):
   ....//some classes
class Task(RefAbstract):
    class Meta(RefAbstract.Meta):
        verbose_name = 'task'
        verbose_name_plural = 'tasks'

class Spatial(models.Model):
    codeq = models.IntegerField('no',help_text='no') 
    code = models.PositiveIntegerField('cutare',primary_key=True,help_text='cutare')//unique column
    codeV = models.IntegerField('novi',help_text='novi') 
    renter = models.ForeignKey(Renter, on_delete=models.DO_NOTHING, verbose_name='renter')
    geometry = models.MultiPolygonField(geography=True, verbose_name='geometry')

    class Meta:
        verbose_name = 'cutarea'
        verbose_name_plural = 'cutarea'


class LScharacteristic(models.Model):
    codels = models.ForeignKey(Spatial, on_delete=models.DO_NOTHING, verbose_name = 'cutarea')// Foreign Key
    tract = models.CharField('tract',max_length = 80, help_text='tract') 
    task = models.ForeignKey(Task,  on_delete=models.DO_NOTHING, verbose_name='task')
    totalarea = models.PositiveIntegerField('totarea',help_text = 'totarea')
    explarea = models.PositiveIntegerField('exarea',help_text = 'exarea')
    protecttype = models.CharField('category',max_length = 50, help_text = 'category')

    class Meta:
        verbose_name = 'characteristic'
        verbose_name_plural = 'characteristics'

class PlannedUsing(models.Model):
    codels = models.ForeignKey(Spatial, on_delete=models.DO_NOTHING, verbose_name = 'cutarea') // Foreign Key   
    codeq = models.IntegerField(help_text='number')
    cutareaShape = models.ForeignKey(CutareaShape, on_delete=models.DO_NOTHING, verbose_name='form')
    cuttype = models.ForeignKey(CutareaType, on_delete=models.DO_NOTHING, verbose_name='type1')
    managetype = models.ForeignKey(ManageType, on_delete=models.DO_NOTHING, verbose_name='type2')
    unit = models.ForeignKey(Unitt, on_delete=models.DO_NOTHING, verbose_name='unit')
    composition = models.ForeignKey(Composition, on_delete=models.DO_NOTHING, verbose_name='sort')
    assortment = models.ForeignKey(Assortment, on_delete=models.DO_NOTHING, verbose_name='assort)
    class Meta:
        verbose_name = 'planus'
        verbose_name_plural = 'planuss'

What is id column? Why id column exist if I don't define them? How I can to fix it?

2
djangodjango-modelsforeign-keysprimary-keymigrate

2 Answers

0
votes

I think that the problem is that your ForeignKey fields do not point explicitly to the field that you have marked as primary (Spatial.code). By marking Spatial.code as primary you prevent Django from creating the id field. See the documentation But if you point a ForeignKey to just a model it will try to link to the id field of that model. To fix this you can add to your ForeignKey field the parameter: to_field='code' and add unique=True to Spatial.code.See documentation

0
votes

You can use 

def __str__(self):
        return self.etat

or 

def __int__(self):

For specif what do you return on your django model. like this:

tests= models.CharField(max_length=100, verbose_name="Test")
class Meta:
        verbose_name = "Tests"
        ordering = ['tests']

    def __str__(self):
        return self.tests