我已经在stackoverflow和google上阅读了很多其他帖子,但我找不到解决方案.
这一切都是在我将模型从CharField更改为ForeignKey时开始的.
我收到的错误是:
Operations to perform: Synchronize unmigrated apps: gis,staticfiles,crispy_forms,geoposition,messages Apply all migrations: venues,images,amenities,cities_light,registration,auth,admin,sites,sessions,contenttypes,easy_thumbnails,newsletter Synchronizing apps without migrations: Creating tables... Running deferred sql... Installing custom sql... Running migrations: Rendering model states... DONE Applying venues.0016_auto_20160514_2141...Traceback (most recent call last): File "/Users/iam-tony/.envs/venuepark/lib/python3.4/site-packages/django/db/backends/utils.py",line 64,in execute return self.cursor.execute(sql,params) psycopg2.IntegrityError: column "venue_city" contains null values
我的模型如下:
class Venue(models.Model): venue_city = models.ForeignKey(City,null=True,) venue_country=models.ForeignKey(Country,null=True)
之前不存在venue_country,因此迁移成功.但是venue_city是CharField.
# -*- coding: utf-8 -*- from __future__ import unicode_literals from django.db import migrations,models class Migration(migrations.Migration): dependencies = [ ('venues','0011_venue_map_activation'),] migrations.Runsql(''' ALTER TABLE venues_venue ALTER venue_city TYPE integer USING venue_city::integer '''),migrations.Runsql(''' ALTER TABLE venues_venue ALTER venue_city RENAME COLUMN venue_city TO venue_city_id '''),migrations.Runsql(''' ALTER TABLE venues_venue ADD CONSTRAINT venues_venus_somefk FOREIGN KEY (venue_city_id) REFERENCES cities_light (id) DEFERRABLE INITIALLY DEFERRED'''),
提前致谢!
更新:我的新迁移文件:
# -*- coding: utf-8 -*- from __future__ import unicode_literals from django.db import migrations,models class Migration(migrations.Migration): dependencies = [ ('cities_light','0006_compensate_for_0003_bytestring_bug'),('venues','0024_remove_venue_venue_city'),] operations = [ migrations.AddField( model_name='venue',name='venue_city',field=models.ForeignKey(null=True,to='cities_light.City'),),]