报错信息：myapp.Article.tags: (fields.W340) null has no effect on ManyToManyField.
解决方法：tags = models.ManyToManyField("Tag") 不用跟null
报错信息：ERRORS:
myapp.Tag.date: (fields.E130) DecimalFields must define a ‘decimal_places‘ attribute.
myapp.Tag.date: (fields.E132) DecimalFields must define a ‘max_digits‘ attribute.
解决方法：DecimalFields字段的“decimal_places(有几位小数) 和 “max_digits（总共有几位数）”
class Account(models.Model): """账户表""" username = models.CharField(max_length=64,unique=True) password = models.CharField(max_length=255) email = models.EmailField(unique=True) register_date = models.DateTimeField(auto_now_add=True) # 注册时间auto_now_add 当前时间，不能被重写 signature = models.CharField("签名",max_length=255,null=True) class Article(models.Model): """文章表""" title = models.CharField(max_length=255,unique=True) context = models.TextField() account = models.ForeignKey("Account",on_delete=models.CASCADE) # models.CASCADE 当用户删除时，文章也删除 tags = models.ManyToManyField("Tag") pub_date = models.DateTimeField() class Tag(models.Model): "标签表" name = models.CharField(max_length=64,unique=True) date = models.DateTimeField(auto_now_add=True)
原文：https://www.cnblogs.com/ljf520hj/p/11716940.html