python - 尝试迁移数据库时出错(slalchemy、slqite3)

Question

我有下一个 models.py 文件:

from app import db, bcrypt
from sqlalchemy import ForeignKey
from sqlalchemy.orm import relationship


class BlogPost(db.Model):

    __tablename__ = "posts"

    id = db.Column(db.Integer, primary_key=True)
    title = db.Column(db.String, nullable=False)
    desc = db.Column(db.String, nullable=False)
    author_id = db.Column(db.Integer, ForeignKey('users.id'))

    def __init__(self, title, desc):
        self.title = title
        self.desc = desc

    def __repr__(self):
        return "Titulo >> " + self.title

class User(db.Model):

    __tablename__ = 'users'

    id = db.Column(db.Integer, primary_key=True)
    name = db.Column(db.String, nullable=False)
    email = db.Column(db.String, nullable=False)
    password = db.Column(db.String, nullable=False)
    posts = relationship("BlogPost", backref="author")

    def __init__(self, name, email, password):
        self.name = name
        self.email = email
        self.password = password

    def __repr__(self):
        return "Usuario >> ", self.name

然后我跑了:

python manage.py db init

一切都很好，问题是当我尝试修改我的模型文件以进行迁移时..我只需更改行:

self.password = password

至:

self.password = bcrypt.generate_password_hash(password)

当我运行时:

python manage.py db migrate

它可以工作，但是当我尝试升级时:

python manage.py db upgrade

我收到下一个错误:

"No support for ALTER of constraints in SQLite dialect")
NotImplementedError: No support for ALTER of constraints in SQLite dialect

注意:数据库只有几条记录用于测试..谢谢!

Answer 1

自大多数 Alembic 教程编写以来，Alembic 已经改变了 SQLite 迁移的完成方式。 ALTER 命令现在需要使用 batch mode 。如果您稍后决定从 SQLite 切换，此模式仍然与其他数据库兼容。

对于每个要更改的表，将所有操作放入 with op.batch_alter_table('table_name'): block 中。

def upgrade():
    with op.batch_alter_table('table_name'):
        op.alter_column(...)