SQLAlchemy classes across files

Question

I\'m trying to figure out how to have SQLAlchemy classes spread across several files, and I can for my life not figure out how to do it. I am pretty new to SQLAlchemy so for

Answer 1

For me, adding import app.tool.tool_entity inside app.py and from app.tool.tool_entity import Tool inside tool/__init__.py was enough to get the table to be created. I haven't tried adding relationship yet, though.

Folder structure:

app/
  app.py
  tool/
    __init__.py
    tool_entity.py
    tool_routes.py

# app/tool/tool_entity.py

from app.base import Base
from sqlalchemy import Column, Integer, String


class Tool(Base):
    __tablename__ = 'tool'

    id = Column(Integer, primary_key=True)
    name = Column(String, nullable=False)
    fullname = Column(String)
    fullname2 = Column(String)
    nickname = Column(String)

    def __repr__(self):
        return "" % (
            self.name, self.fullname, self.nickname)

# app/tool/__init__.py
from app.tool.tool_entity import Tool

# app/app.py

from flask import Flask
from sqlalchemy import create_engine
from app.tool.tool_routes import tool_blueprint
from app.base import Base


db_dialect = 'postgresql'
db_user = 'postgres'
db_pwd = 'postgrespwd'
db_host = 'db'
db_name = 'db_name'
engine = create_engine(f'{db_dialect}://{db_user}:{db_pwd}@{db_host}/{db_name}', echo=True)
Base.metadata.create_all(engine)


app = Flask(__name__)
@app.route('/')
def hello_world():
    return 'hello world'


app.register_blueprint(tool_blueprint, url_prefix='/tool')

if __name__ == '__main__':
    # you can add this import here, or anywhere else in the file, as debug (watch mode) is on, 
    # the table should be created as soon as you save this file.
    import app.tool.tool_entity
    app.run(host='0.0.0.0', port=5000, debug=True)