# Importing simple table to Django seems to generate extraneous field **URL:** \ **Category:** Using Django\ **Created:** [September 4, 2024, 8:23am UTC](https://forum.djangoproject.com/t/importing-simple-table-to-django-seems-to-generate-extraneous-field/34481 "2024-09-04T08:23:28Z")\ **Posts on this page:** 2\ **Page:** 1
**Author:** ![acb764se](https://sea2.discourse-cdn.com/flex026/user_avatar/forum.djangoproject.com/acb764se/32/21255_2.png) [@acb764se](https://forum.djangoproject.com/u/acb764se)\ **Post date:** [September 4, 2024, 8:23am UTC](https://forum.djangoproject.com/t/importing-simple-table-to-django-seems-to-generate-extraneous-field/34481/1 "2024-09-04T08:23:28Z")
This is my table as defined in `MySQL`: ```auto mysql> describe rules_enabled; +-------------------+----------------------------------+------+-----+---------+----------------+ | Field | Type | Null | Key | Default | Extra | +-------------------+----------------------------------+------+-----+---------+----------------+ | rule_id | int | NO | PRI | NULL | auto_increment | | rule_name | varchar(20) | NO | MUL | NULL | | | role_name | varchar(20) | NO | MUL | NULL | | | role_dependency | varchar(20) | YES | MUL | NULL | | | range_application | enum('PERIOD','WIDE','REF_DATE') | NO | | PERIOD | | | range_duration | int | YES | | -1 | | | reference_date | timestamp | YES | | NULL | | | rule_parameters | json | YES | | NULL | | +-------------------+----------------------------------+------+-----+---------+----------------+ ``` and this is how it is understood by Django doing `manage.py inspectdb rules_enabled`: ```auto class RulesEnabled(models.Model): rule_id = models.AutoField(unique=True) rule_name = models.CharField(max_length=20, db_comment='Rule name') role_name = models.ForeignKey('ShiftRoles', models.DO_NOTHING, db_column='role_name') role_dependency = models.ForeignKey('ShiftRoles', models.DO_NOTHING, db_column='role_dependency', related_name='rulesenabled_role_dependency_set', blank=True, null=True) range_application = models.CharField(max_length=8, db_comment='Type of range used to evaluae the rule.') range_duration = models.IntegerField(blank=True, null=True, db_comment='Extension of the range (WIDE Only) in days.') reference_date = models.DateTimeField(blank=True, null=True, db_comment='Reference day (REF_DATE ONLY).') rule_parameters = models.JSONField(blank=True, null=True, db_comment='Rule parameters') class Meta: managed = False db_table = 'rules_enabled' db_table_comment = 'Rules associated to the defined roles' ``` problem 1, using it like this in file `models.py`, running `manage.py makemigrations` gives: ```auto File "/usr/local/django_venv/lib/python3.10/site-packages/django/db/models/fields/ __init__.py", line 2812, in contribute_to_class raise ValueError( ValueError: Model b2mmsdb.RulesEnabled can't have more than one auto-generated field. ``` (I think this is because of the Django-created extra id, it doesn’t like the name of my own PK) Next, I change line ```auto rule_id = models.AutoField(unique=True) ``` to ```auto rule_id = models.AutoField(primary_key=True) ``` Django does allright `makemigrations` and `migrate` but now, in the Django shell, I get: ```auto >>> rule_205=RulesEnabled.objects.filter(rule_id=205).get() >>> print(rule_205.rule_name) overlap <--------------fantastic! it's even right! >>> RulesEnabled.objects.filter(rule_name='overlap').count() 23 <------still OK. But, waitaminute..... >>> print(rule_205.role_name) Traceback (most recent call last): File "/usr/local/django_venv/lib/python3.10/site-packages/django/db/models/fields/related_descriptors.py", line 236, in __get__ rel_obj = self.field.get_cached_value(instance) File "/usr/local/django_venv/lib/python3.10/site-packages/django/db/models/fields/mixins.py", line 15, in get_cached_value return instance._state.fields_cache[cache_name] KeyError: 'role_name' <---------------- huh? (....more traceback from Django innards...) ValueError: Field 'role_id' expected a number but got 'cr_shadow_loc'. >>> RulesEnabled.objects.filter(role_name='cr_shadow_loc').count() Traceback (most recent call last): File "/usr/local/django_venv/lib/python3.10/site-packages/django/db/models/fields/ __init__.py", line 2117, in get_prep_value return int(value) ValueError: invalid literal for int() with base 10: 'cr_shadow_loc' .... ValueError: Field 'role_id' expected a number but got 'cr_shadow_loc'. ``` Now, where does `role_id` come from, and why Django seems to believe is a PK? Let’s have a look at all fields: ```auto >>> field_names = [f.name for f in RulesEnabled._meta.get_fields()] >>> print(field_names) ['rule_id', 'rule_name', 'role_name', 'role_dependency', 'range_application', 'range_duration', 'reference_date', 'rule_parameters'] ``` No `role_id` that I can see. This is not the first table I import to Django, have seen and fixed other strange facts, but can’t figure out this at all. Please help, or suggest other debugging shell commands. Thank you!! ---
**Author:** ![acb764se](https://sea2.discourse-cdn.com/flex026/user_avatar/forum.djangoproject.com/acb764se/32/21255_2.png) [@acb764se](https://forum.djangoproject.com/u/acb764se)\ **Post date:** [September 4, 2024, 9:10am UTC](https://forum.djangoproject.com/t/importing-simple-table-to-django-seems-to-generate-extraneous-field/34481/2 "2024-09-04T09:10:07Z")
Well, it happens that role\_id is in _another_ table, and it comes into play because role\_name in my malfunctioning table is a FK relation to that. So, I have to add a clause to\_field, changing line: ```auto role_name = models.ForeignKey('ShiftRoles', models.DO_NOTHING, db_column='role_name') ``` to ```auto role_name = models.ForeignKey('ShiftRoles', models.DO_NOTHING, db_column='role_name',to_field='role_name') ``` As simple as that. Thanks for reading!