在表“page_content_pagesection”上插入或更新违反了外键约束答案

【问题标题】：insert or update on table "page_content_pagesection" violates foreign key constraint在表“page_content_pagesection”上插入或更新违反了外键约束
【发布时间】：2018-03-09 05:31:58
【问题描述】：

我只是在本地对我的 Django 模型进行了一些更改，为它们进行了迁移，并将这些迁移推送到我的生产服务器。在本地一切正常，但是当我尝试在生产服务器中执行迁移时，出现此错误。零指数让我失望。它所依赖的模型，teamsafetytracker 是新的，并且页面部分到目前为止从未依赖它，所以我不确定它为什么还要在 teamsafetytracker 表中寻找实例？

django.db.utils.IntegrityError: insert or update on table "page_content_pagesection" violates foreign key constraint "page_co_safety_tracker_id_f30c4360_fk_team_teamsafetytracker_id"
DETAIL:  Key (safety_tracker_id)=(0) is not present in table "team_teamsafetytracker".

相关迁移

class Migration(migrations.Migration):

dependencies = [
    ('team', '0037_remove_teampagesection_multi_tracker_one'),
]

operations = [
    migrations.RemoveField(
        model_name='team',
        name='safety_clock_start',
    ),
]


class Migration(migrations.Migration):

dependencies = [
    ('team', '0038_remove_team_safety_clock_start'),
    ('page_content', '0017_auto_20170926_1436'),
]

operations = [
    migrations.RemoveField(
        model_name='webpage',
        name='safety_clock_start',
    ),
    migrations.AddField(
        model_name='pagesection',
        name='multi_tracker_three',
        field=models.ForeignKey(blank=True, null=True, on_delete=django.db.models.deletion.CASCADE, related_name='page_multi_three', to='team.TeamSafetyTracker'),
    ),
    migrations.AddField(
        model_name='pagesection',
        name='multi_tracker_two',
        field=models.ForeignKey(blank=True, null=True, on_delete=django.db.models.deletion.CASCADE, related_name='page_multi_two', to='team.TeamSafetyTracker'),
    ),
    migrations.AddField(
        model_name='pagesection',
        name='tracker_side',
        field=models.CharField(choices=[(b'L', b'Left'), (b'T', b'Three Section'), (b'R', b'Right')], default=b'R', max_length=20),
    ),
    migrations.AlterField(
        model_name='pagesection',
        name='safety_tracker',
        field=models.ForeignKey(blank=True, null=True, on_delete=django.db.models.deletion.CASCADE, related_name='page_section', to='team.TeamSafetyTracker'),
    ),
]

型号

class TeamSafetyTracker(models.Model):
    name = models.CharField(max_length=255)

    label = models.CharField(max_length=200)

    team = models.ForeignKey('Team')

    safety_clock_start = models.DateTimeField(help_text="Date Since Last Accident. Used if You Have Page Sections That Include a Safety Tracker", null=True, blank=True)

    create_date = models.DateTimeField(auto_now_add=True)

    class Meta:
        verbose_name = 'Team Safety Tracker'
        verbose_name_plural = 'Team Safety Trackers'

    def __str__(self):
        return self.name

class PageSection(models.Model):
    page = models.ForeignKey(WebPage)
    title = models.CharField(max_length=255, null=True, blank=True)
    content = models.TextField(null=True, blank=True)

    has_gallery = models.BooleanField(default=False)
    gallery = models.ForeignKey('PhotoGallery', null=True, blank=True)

    safety_tracker = models.ForeignKey(TeamSafetyTracker, related_name='page_section', null=True, blank=True)

    multi_tracker_two = models.ForeignKey(TeamSafetyTracker, related_name='page_multi_two', null=True, blank=True)
    multi_tracker_three = models.ForeignKey(TeamSafetyTracker, related_name='page_multi_three', null=True, blank=True)

    tracker_side = models.CharField(max_length=20, choices=TRACKER_SIDES, default='R')

    background_choices = models.CharField(max_length=100, choices=BACKGROUND_CHOICES, default='WH')

    display_order = models.IntegerField(default=1)
    is_published = models.BooleanField(default=True)

    def __str__(self):
        return ('Section %s') % self.display_order

    class Meta:
        verbose_name = 'Section'
        verbose_name_plural = 'Sections'
        ordering = ('display_order',)

    def gallery_sets(self):
        if self.gallery:
            gallery_photos = self.gallery.photos.filter(is_published=True)

            set_1 = gallery_photos[:10]

            gallery_sets = [set_1]

            if gallery_photos.count() > 10:
                set_2 = gallery_photos[10:20]
                gallery_sets.append(set_2)

            if gallery_photos.count() > 20:
                set_3 = gallery_photos[20:30]
                gallery_sets.append(set_3)

            if gallery_photos.count() > 30:
                set_4 = gallery_photos[30:40]
                gallery_sets.append(set_4)

            if gallery_photos.count() > 40:
                set_5 = gallery_photos[40:50]
                gallery_sets.append(set_5)

            return gallery_sets
        else:
            return []

    @staticmethod
    def get_published_objects():
        objects = PageSection.objects.filter(is_published=True).order_by('display_order')

        return objects

追溯

Running migrations:
  Rendering model states... DONE
  Applying team.0032_teamsafetytracker... OK
  Applying team.0033_auto_20180306_1928... OK
  Applying team.0034_auto_20180306_1942... OK
  Applying team.0035_auto_20180306_1944... OK
  Applying team.0036_auto_20180306_1953... OK
  Applying team.0037_remove_teampagesection_multi_tracker_one... OK
  Applying team.0038_remove_team_safety_clock_start... OK
  Applying page_content.0018_auto_20180307_1851...Traceback (most recent call last):
  File "/usr/local/lib/python3.5/dist-packages/django/db/backends/utils.py", line 64, in execute
    return self.cursor.execute(sql, params)
psycopg2.IntegrityError: insert or update on table "page_content_pagesection" violates foreign key constraint "page_co_safety_tracker_id_f30c4360_fk_team_teamsafetytracker_id"
DETAIL:  Key (safety_tracker_id)=(0) is not present in table "team_teamsafetytracker".


The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "manage.py", line 15, in <module>
    execute_from_command_line(sys.argv)
  File "/usr/local/lib/python3.5/dist-packages/django/core/management/__init__.py", line 353, in execute_from_command_line
    utility.execute()
  File "/usr/local/lib/python3.5/dist-packages/django/core/management/__init__.py", line 345, in execute
    self.fetch_command(subcommand).run_from_argv(self.argv)
  File "/usr/local/lib/python3.5/dist-packages/django/core/management/base.py", line 348, in run_from_argv
    self.execute(*args, **cmd_options)
  File "/usr/local/lib/python3.5/dist-packages/django/core/management/base.py", line 399, in execute
    output = self.handle(*args, **options)
  File "/usr/local/lib/python3.5/dist-packages/django/core/management/commands/migrate.py", line 200, in handle
    executor.migrate(targets, plan, fake=fake, fake_initial=fake_initial)
  File "/usr/local/lib/python3.5/dist-packages/django/db/migrations/executor.py", line 92, in migrate
    self._migrate_all_forwards(plan, full_plan, fake=fake, fake_initial=fake_initial)
  File "/usr/local/lib/python3.5/dist-packages/django/db/migrations/executor.py", line 121, in _migrate_all_forwards
    state = self.apply_migration(state, migration, fake=fake, fake_initial=fake_initial)
  File "/usr/local/lib/python3.5/dist-packages/django/db/migrations/executor.py", line 198, in apply_migration
    state = migration.apply(state, schema_editor)
  File "/usr/local/lib/python3.5/dist-packages/django/db/migrations/migration.py", line 123, in apply
    operation.database_forwards(self.app_label, schema_editor, old_state, project_state)
  File "/usr/local/lib/python3.5/dist-packages/django/db/migrations/operations/fields.py", line 201, in database_forwards
    schema_editor.alter_field(from_model, from_field, to_field)
  File "/usr/local/lib/python3.5/dist-packages/django/db/backends/base/schema.py", line 482, in alter_field
    old_db_params, new_db_params, strict)
  File "/usr/local/lib/python3.5/dist-packages/django/db/backends/postgresql/schema.py", line 116, in _alter_field
    new_db_params, strict,
  File "/usr/local/lib/python3.5/dist-packages/django/db/backends/base/schema.py", line 717, in _alter_field
    self.execute(self._create_fk_sql(model, new_field, "_fk_%(to_table)s_%(to_column)s"))
  File "/usr/local/lib/python3.5/dist-packages/django/db/backends/base/schema.py", line 110, in execute
    cursor.execute(sql, params)
  File "/usr/local/lib/python3.5/dist-packages/django/db/backends/utils.py", line 64, in execute
    return self.cursor.execute(sql, params)
  File "/usr/local/lib/python3.5/dist-packages/django/db/utils.py", line 95, in __exit__
    six.reraise(dj_exc_type, dj_exc_value, traceback)
  File "/usr/local/lib/python3.5/dist-packages/django/utils/six.py", line 685, in reraise
    raise value.with_traceback(tb)
  File "/usr/local/lib/python3.5/dist-packages/django/db/backends/utils.py", line 64, in execute
    return self.cursor.execute(sql, params)
django.db.utils.IntegrityError: insert or update on table "page_content_pagesection" violates foreign key constraint "page_co_safety_tracker_id_f30c4360_fk_team_teamsafetytracker_id"
DETAIL:  Key (safety_tracker_id)=(0) is not present in table "team_teamsafetytracker".

【问题讨论】：

标签： django models migrate

【解决方案1】：

这似乎是该 Pagesection 表中旧值的问题，即。有一个 PageSection 条目，其中 safety_tracker 已经为 0（该字段以前是一个 IntegerField）。当您将其更改为 TeamSafetyTracker 的 ForeignKey 时，Django 尝试将旧值与 TeamSafetyTracker ID 匹配。

在运行 page_content.0018_auto_20180307_1851 迁移之前，确保列 safety_tracker 的所有值都设置为 null。您可以创建自定义迁移来执行此操作。

【讨论】：

感谢 Ghariani，这帮助了 :)