在 Django (Django 3.0) 中将现有 id 转换为 uuid 后修复错误“格式错误的十六进制 UUID 字符串”

Question

I created a table with an initial IntegerField primary key and later changed the id to a UUIDField. Now this raises a "Badly formed hexadecimal UUID string" , I guess because a number such as "1" isn't a valid UUID value. Does anyone know a concise way to fix this in code when updating the models.py file for the django app?

Answer 1

Before everything, double check that you don't have any foreign key with Cascade uppon this model. Then, instead of changing the type of id = models.IntegerField() :

• create a new field uuid = models.UUIDField(default=uuid.uuid4, primary=True) (default will set the field for existing rows)
• make migrations
• remove the id field
• make migrations
• rename the uuid field to id
• make migrations
• migrate

However, you should know that removing the id field, and / or naming the uuid is not mandatory, and it's often a good idea to keep both.