如何将列添加到现有表？ 在 Flask SqlAlchemy

Question

I have a flask SqlAclchemy table called User:

class User(db.Model):
    id = db.Column(db.INTEGER, primary_key=True)
    username = db.Column(db.String(64), index=True, unique=True)

i have now edited it and added this line; favCol = db.Column(db.String(12))

how do i update the table for it to recognize this new colum when i add a new user? At the moment when i create a User like User(username="bob",favCol="red") it gives me an error:

TypeError: 'favCol' is an invalid keyword argument for User

I have heard of solution with Migrate although i would prefer re a simpler solution if possible

Answer 1

If you don't care about the data in the database getting erased. You can do the following:

from terminal if 'py' doesn't start python, try 'python'. press enter after each of these commands

py
from projectdirectory import db
db.drop_all()
db.create_all()

If you care about your existing data, you need to use something like flask_migrate which uses alembic in order to help you do database migrations while maintaining your data.