flask-sqlalchemy

问题 Assuming the following models: class Worker(Model): __tablename__ = 'workers' ... jobs = relationship('Job', back_populates='worker', order_by='desc(Job.started)', lazy='dynamic') @hybrid_property def latest_job(self): return self.jobs.first() # jobs already ordered descending @latest_job.expression def latest_job(cls): Job = db.Model._decl_class_registry.get('Job') return select([func.max(Job.started)]).where(cls.id == Job.worker_id).as_scalar() class Job(Model): ... started = db.Column(db

问题 I got a VPS and I wanted to host my flask app there. I followed DigitalOcean's tutorial on "How To Serve Flask Applications with Gunicorn and Nginx on Ubuntu 18.04" (I didnt get the VPS from DO) and everything worked fine with the example app... when I tried to replace the files with my app's files and host the app again I get a 500 error. The 500 error doesnt appear everywhere. It comes up where my .db file is envoled like where I have posts or users etc.. Everything else loads up fine. The

问题 I got a VPS and I wanted to host my flask app there. I followed DigitalOcean's tutorial on "How To Serve Flask Applications with Gunicorn and Nginx on Ubuntu 18.04" (I didnt get the VPS from DO) and everything worked fine with the example app... when I tried to replace the files with my app's files and host the app again I get a 500 error. The 500 error doesnt appear everywhere. It comes up where my .db file is envoled like where I have posts or users etc.. Everything else loads up fine. The

问题 I have a bit of experience with Flask but not very much with databases (Flask-migrate / alembic / SqlAlchemy). I'm following this tutorial and things are working quite alright. I have a User model like this: # user_model.py from app import DB ... other imports class User(UserMixin, DB.Model): __tablename__ = 'users' id = DB.Column(DB.Integer, primary_key=True) username = DB.Column(DB.String(64), index=True, unique=True) email = DB.Column(DB.String(120), index=True, unique=True) password_hash

问题 I have a bit of experience with Flask but not very much with databases (Flask-migrate / alembic / SqlAlchemy). I'm following this tutorial and things are working quite alright. I have a User model like this: # user_model.py from app import DB ... other imports class User(UserMixin, DB.Model): __tablename__ = 'users' id = DB.Column(DB.Integer, primary_key=True) username = DB.Column(DB.String(64), index=True, unique=True) email = DB.Column(DB.String(120), index=True, unique=True) password_hash

问题 I am trying to execute a stored procedure on Mysql database with sqlalchemy. It runs fine from the shell but throws this error: OperationalError: (MySQLdb._exceptions.OperationalError) (1568, "Transaction characteristics can't be changed while a transaction is in progress") The reason as it seems is that SQLAlchemy runs query within a transaction. And the transaction within the stored procedure is conflicting with it. Below is sqlalchemy log: 2019-07-24 15:20:28,888 INFO sqlalchemy.engine

问题 I am trying to execute a stored procedure on Mysql database with sqlalchemy. It runs fine from the shell but throws this error: OperationalError: (MySQLdb._exceptions.OperationalError) (1568, "Transaction characteristics can't be changed while a transaction is in progress") The reason as it seems is that SQLAlchemy runs query within a transaction. And the transaction within the stored procedure is conflicting with it. Below is sqlalchemy log: 2019-07-24 15:20:28,888 INFO sqlalchemy.engine

问题 I am trying to execute a stored procedure on Mysql database with sqlalchemy. It runs fine from the shell but throws this error: OperationalError: (MySQLdb._exceptions.OperationalError) (1568, "Transaction characteristics can't be changed while a transaction is in progress") The reason as it seems is that SQLAlchemy runs query within a transaction. And the transaction within the stored procedure is conflicting with it. Below is sqlalchemy log: 2019-07-24 15:20:28,888 INFO sqlalchemy.engine

问题 Currently, I run $ flask db init $ flask db migrate -m "initialization" $ flask db upgrade if the database does not exist. I would like to run this within Python, e.g. something like app.create_db() so that I don't have to care about setting the database up. Is that possible? I use the flask-sqlalchemy and flask-migrations plugins 回答1: Obviously, you have installed flask-migrate, flask-sqlalchemy . So, you can do like this: from flask_sqlalchemy import SQLAlchemy from flask import Flask app =

问题 This is model code, I have tested this code, it is no error and it can create tables, records in DB createdb.py app = Flask(__name__) app.config['SQLALCHEMY_DATABASE_URI'] = 'mysql+pymysql://root:@localhost:3306/ai' db = SQLAlchemy(app) if __name__ == 'createdb': db.reflect() db.drop_all() db = SQLAlchemy(app) class Class(db.Model): id = db.Column(db.Integer, primary_key=True, unique=True, autoincrement=True) label = db.Column(db.String(255), unique=True, nullable=False) def __init__(self,