在不使用Flask的情况下使用Flask-SQLAlchemy [英] Using Flask-SQLAlchemy without Flask

问题描述

我有一个使用 Flask 和 Flask-SQLAlchemy 构建的小型Web服务，仅包含一个模型.现在，我想使用相同的数据库，但使用命令行应用程序，因此我想删除 Flask 依赖项.

I had a small web service built using Flask and Flask-SQLAlchemy that only held one model. I now want to use the same database, but with a command line app, so I'd like to drop the Flask dependency.

我的模型如下:

class IPEntry(db.Model):
    id = db.Column(db.Integer, primary_key=True)
    ip_address = db.Column(db.String(16), unique=True)
    first_seen = db.Column(db.DateTime(),
        default = datetime.datetime.utcnow
    )
    last_seen = db.Column(db.DateTime(),
        default = datetime.datetime.utcnow
    )

    @validates('ip')
    def validate_ip(self, key, ip):
        assert is_ip_addr(ip)
        return ip

由于 db 将不再是 flask.ext.sqlalchemy.SQLAlchemy(app)的引用，因此如何转换模型以仅使用SQLAlchemy.两种应用程序(使用 Flask-SQLAlchemy 的其他应用程序和使用 SQLAlchemy 的其他应用程序)是否可以使用同一数据库?

Since db will no longer be a reference to flask.ext.sqlalchemy.SQLAlchemy(app), how can I convert my model to use just SQLAlchemy. Is there a way for the two applications (one with Flask-SQLAlchemy the other with SQLAlchemy) to use the same database?

推荐答案

您可以执行此操作以替换 db.Model :

you can do this to replace db.Model:

from sqlalchemy import orm
from sqlalchemy.ext.declarative import declarative_base
import sqlalchemy as sa

base = declarative_base()
engine = sa.create_engine(YOUR_DB_URI)
base.metadata.bind = engine
session = orm.scoped_session(orm.sessionmaker())(bind=engine)

# after this:
# base == db.Model
# session == db.session
# other db.* values are in sa.*
# ie: old: db.Column(db.Integer,db.ForeignKey('s.id'))
#     new: sa.Column(sa.Integer,sa.ForeignKey('s.id'))
# except relationship, and backref, those are in orm
# ie: orm.relationship, orm.backref
# so to define a simple model

class UserModel(base):
    __tablename__ = 'users' #<- must declare name for db table
    id = sa.Column(sa.Integer,primary_key=True)
    name = sa.Column(sa.String(255),nullable=False)

然后创建表:

 base.metadata.create_all()

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