python - django 部署到heroku 如何删除数据库

Question

model 中新增了一个对象 Message 和 并在另一个model中增加外键字段message，然后push到heroku上，同步migrate之后，发现新的表不能用. 但是本地是执行 python manage.py flush 之后同步的，没出问题， 但是在heroku上执行 flush 出错

CommandError: Database d4e4561s5hscht couldn't be flushed. Possible reasons:
  * The database isn't running or isn't configured correctly.
  * At least one of the expected database tables doesn't exist.
  * The SQL was invalid.
Hint: Look at the output of 'django-admin sqlflush'. That's the SQL this command wasn't able to run.
The full error: cannot truncate a table referenced in a foreign key constraint
DETAIL:  Table "blog_post" references "auth_user".
HINT:  Truncate table "blog_post" at the same time, or use TRUNCATE ... CASCADE.

请问怎么清理数据库

Answer 1

There is a field foreign key in the "blog_post" table that is associated with the "auth_user" table.
Flush is for truncate table. Of course, the auth_user table cannot truncate if it has data.

The usual approach in the current version is:

python manage.py makemigrations
python manage.py migrate

That’s it. I don’t know what LZ said “after migrating, the new watch cannot be used”

Why flush? Everything is already online. Still need to clear the data?