原因 执行命令 python manage.py makemigrations 报错 TypeError: __init__() missing 1 required positional argument: 'on_delete' 定义外键报错 解决办法 字段名称 = models.ForeignKey('表名', on_delete=models.CASCADE) on_delete=models.CASCADE 在 django2.0之前有默认值,之后版本就需要显式指定…

在执行python manage.py makemigrations时报错: TypeError: __init__() missing 1 required positional argument: 'on_delete' 解决方法: 在连接外键时加上: on_delete=models.CASCADE…

sgrade = models.ForeignKey("Grades",) 执行python manage.py makemigrations后出现TypeError: __init__() missing 1 required positional argument: 'on_delete'缺少一个参数  'on_delete'加上就好了sgrade = models.ForeignKey("Grades",on_delete=models.CASCADE,)…

原因及解决办法: https://www.cnblogs.com/phyger/p/8035253.html…

原因: 在django2.0后,定义外键和一对一关系的时候需要加on_delete选项,此参数为了避免两个表里的数据不一致问题,不然会报错:TypeError: __init__() missing 1 required positional argument: 'on_delete'举例说明:user=models.OneToOneField(User)owner=models.ForeignKey(UserProfile)需要改成:user=models.OneToOneField(User…

原因: 在django2.0后,定义外键和一对一关系的时候需要加on_delete选项,此参数为了避免两个表里的数据不一致问题,不然会报错:TypeError: __init__() missing 1 required positional argument: 'on_delete'举例说明:user=models.OneToOneField(User)owner=models.ForeignKey(UserProfile)需要改成:user=models.OneToOneField(User…

问题:在执行python manage.py makemigrations learning_logs时,系统会报错,提示:TypeError: __init__() missing 1 required positional argument: 'on_delete' (ll_env) c:\WorkSpace\SimpleTest\learning_log>python manage.py makemigrations learning_logsTraceback (most recent…

进行数据库迁移的时候,显示  TypeError: __init__() missing 1 required positional argument: 'on_delete' 图示: 出现原因: 在django2.0后,定义外键和一对一关系的时候需要加on_delete选项,此参数为了避免两个表里的数据不一致问题,不然会报错: TypeError: __init__() missing 1 required positional argument: 'on_delete' 修改:…

python: 3.6.4 django: 2.0 models.py 代码如下 # coding: utf-8 from django.db import models from django.contrib.auth.models import User # Create your models here. class Category(models.Model): name = models.CharField(max_length=100) class Tag(models.Model)…

RuntimeError: Model class app_anme.models.xxx doesn't declare an explicit app_label and isn't in an application in INSTALLED_APPS. 将app加入settings的INSTALLED_APPS 中…