id summary reporter owner description type status component version severity resolution keywords cc stage has_patch needs_docs needs_tests needs_better_patch easy ui_ux 24853 FK value not inserted in database in data migration Rakan Alhneiti nobody "Hello, I am using ""django_dynamic_scraper"" to scrape data off the internet. I started my project by creating an empty migration that basically adds a default scraper. Models as defined in dynamic_scraper app: {{{ class ScrapedObjClass(models.Model): name = models.CharField(max_length=200) scraper_scheduler_conf = models.TextField(default='\ ""MIN_TIME"": 15,\n\ ""MAX_TIME"": 10080,\n\ ""INITIAL_NEXT_ACTION_FACTOR"": 10,\n\ ""ZERO_ACTIONS_FACTOR_CHANGE"": 20,\n\ ""FACTOR_CHANGE_FACTOR"": 1.3,\n') checker_scheduler_conf = models.TextField(default='\ ""MIN_TIME"": 1440,\n\ ""MAX_TIME"": 10080,\n\ ""INITIAL_NEXT_ACTION_FACTOR"": 1,\n\ ""ZERO_ACTIONS_FACTOR_CHANGE"": 5,\n\ ""FACTOR_CHANGE_FACTOR"": 1.3,\n') comments = models.TextField(blank=True) def __unicode__(self): return self.name class Meta: ordering = ['name',] class ScrapedObjAttr(models.Model): ATTR_TYPE_CHOICES = ( ('S', 'STANDARD'), ('T', 'STANDARD (UPDATE)'), ('B', 'BASE'), ('U', 'DETAIL_PAGE_URL'), ('I', 'IMAGE'), ) name = models.CharField(max_length=200) obj_class = models.ForeignKey(ScrapedObjClass) attr_type = models.CharField(max_length=1, choices=ATTR_TYPE_CHOICES) def __unicode__(self): return self.name + "" ("" + self.obj_class.__unicode__() + "")"" }}} Here's my migration: {{{ # -*- coding: utf-8 -*- from __future__ import unicode_literals from django.db import models, migrations def add_youtube_scraper(apps, schema_editor): Scraper = apps.get_model('dynamic_scraper', 'Scraper') ScrapedObjClass = apps.get_model('dynamic_scraper', 'ScrapedObjClass') ScrapedObjAttr = apps.get_model('dynamic_scraper', 'ScrapedObjAttr') ScraperElem = apps.get_model('dynamic_scraper', 'ScraperElem') scraped_obj_class = ScrapedObjClass() scraped_obj_class.name = 'Youtube Video' scraped_obj_class.save() scraped_attrs_map = {} scraped_attrs_list = [ {'name': 'base', 'type': 'B'}, {'name': 'url', 'type': 'U'}, {'name': 'title', 'type': 'S'}, {'name': 'body', 'type': 'S'}, {'name': 'images', 'type': 'I'}, {'name': 'videos', 'type': 'S'}, ] for scraped_attr in scraped_attrs_list: scraped_obj_attr = ScrapedObjAttr() scraped_obj_attr.name = scraped_attr['name'] scraped_obj_attr.attr_type = scraped_attr['type'] scraped_obj_attr.obj_class_id = scraped_obj_class.id scraped_obj_attr.save() scraped_attrs_map[scraped_attr['name']] = scraped_obj_attr class Migration(migrations.Migration): dependencies = [ ] operations = [ migrations.RunPython(add_youtube_scraper) ] }}} When i run python manage.py migrate i get the following error: {{{ Running migrations: Applying content_scraper.0001_initial... Traceback (most recent call last): File ""./manage.py"", line 11, in execute_from_command_line(sys.argv) File ""/usr/local/lib/python2.7/site-packages/django/core/management/__init__.py"", line 385, in execute_from_command_line utility.execute() File ""/usr/local/lib/python2.7/site-packages/django/core/management/__init__.py"", line 377, in execute self.fetch_command(subcommand).run_from_argv(self.argv) File ""/usr/local/lib/python2.7/site-packages/django/core/management/base.py"", line 288, in run_from_argv self.execute(*args, **options.__dict__) File ""/usr/local/lib/python2.7/site-packages/django/core/management/base.py"", line 338, in execute output = self.handle(*args, **options) File ""/usr/local/lib/python2.7/site-packages/django/core/management/commands/migrate.py"", line 161, in handle executor.migrate(targets, plan, fake=options.get(""fake"", False)) File ""/usr/local/lib/python2.7/site-packages/django/db/migrations/executor.py"", line 68, in migrate self.apply_migration(migration, fake=fake) File ""/usr/local/lib/python2.7/site-packages/django/db/migrations/executor.py"", line 102, in apply_migration migration.apply(project_state, schema_editor) File ""/usr/local/lib/python2.7/site-packages/django/db/migrations/migration.py"", line 108, in apply operation.database_forwards(self.app_label, schema_editor, project_state, new_state) File ""/usr/local/lib/python2.7/site-packages/django/db/migrations/operations/special.py"", line 117, in database_forwards self.code(from_state.render(), schema_editor) File ""/app/content_scraper/migrations/0001_initial.py"", line 32, in add_youtube_scraper scraped_obj_attr.save() File ""/usr/local/lib/python2.7/site-packages/django/db/models/base.py"", line 589, in save force_update=force_update, update_fields=update_fields) File ""/usr/local/lib/python2.7/site-packages/django/db/models/base.py"", line 617, in save_base updated = self._save_table(raw, cls, force_insert, force_update, using, update_fields) File ""/usr/local/lib/python2.7/site-packages/django/db/models/base.py"", line 698, in _save_table result = self._do_insert(cls._base_manager, using, fields, update_pk, raw) File ""/usr/local/lib/python2.7/site-packages/django/db/models/base.py"", line 731, in _do_insert using=using, raw=raw) File ""/usr/local/lib/python2.7/site-packages/django/db/models/manager.py"", line 92, in manager_method return getattr(self.get_queryset(), name)(*args, **kwargs) File ""/usr/local/lib/python2.7/site-packages/django/db/models/query.py"", line 921, in _insert return query.get_compiler(using=using).execute_sql(return_id) File ""/usr/local/lib/python2.7/site-packages/django/db/models/sql/compiler.py"", line 921, in execute_sql cursor.execute(sql, params) File ""/usr/local/lib/python2.7/site-packages/django/db/backends/utils.py"", line 82, in execute return super(CursorDebugWrapper, self).execute(sql, params) File ""/usr/local/lib/python2.7/site-packages/django/db/backends/utils.py"", line 65, in execute return self.cursor.execute(sql, params) File ""/usr/local/lib/python2.7/site-packages/django/db/utils.py"", line 94, in __exit__ six.reraise(dj_exc_type, dj_exc_value, traceback) File ""/usr/local/lib/python2.7/site-packages/django/db/backends/utils.py"", line 65, in execute return self.cursor.execute(sql, params) django.db.utils.IntegrityError: null value in column ""obj_class_id"" violates not-null constraint DETAIL: Failing row contains (19, base, null, B). }}} Basically what i am trying to do is assign a value to a ForeignKey. I tried printing the value of the created scraper object class and it's 19 as in the last line of the traceback. I also checked the SQL statement generated: {{{ INSERT INTO ""dynamic_scraper_scrapedobjattr"" (""name"", ""attr_type"") VALUES (%s, %s) RETURNING ""dynamic_scraper_scrapedobjattr"".""id"" }}} As you can see the obj_class attribute of the ScrapedObjAttr is omitted, which is a weird behaviour." Uncategorized closed Database layer (models, ORM) 1.7 Normal wontfix database, migrations Unreviewed 0 0 0 0 0 0