如何从sqlalchemy数据库返回flask中的文件

from flask import Flask, send_file
from flask_sqlalchemy import SQLAlchemy

app = Flask(__name__)
app.config['SQLALCHEMY_DATABASE_URI'] = 'your_database_uri'
db = SQLAlchemy(app)

class File(db.Model):
    id = db.Column(db.Integer, primary_key=True)
    name = db.Column(db.String(100))
    path = db.Column(db.String(200))

@app.route('/download/<int:file_id>')
def download_file(file_id):
    file = File.query.get(file_id)
    if file:
        return send_file(file.path, attachment_filename=file.name, as_attachment=True)
    else:
        return 'File not found'

file1 = File(name='example1.txt', path='/path/to/example1.txt')
file2 = File(name='example2.txt', path='/path/to/example2.txt')
db.session.add_all([file1, file2])
db.session.commit()

if __name__ == '__main__':
    app.run()