Ошибка при использовании Sqlalchemy + Heroku Postgresql DB?

Question

RaymanPy @RaymanPy

PostgreSQL

Ошибка при использовании Sqlalchemy + Heroku Postgresql DB?

Код:

Код

from sqlalchemy import Integer,String, DateTime ,Column, ForeignKeyConstraint, UniqueConstraint, ForeignKey
from sqlalchemy.orm import sessionmaker
from sqlalchemy.orm import relationship
from sqlalchemy.orm import scoped_session
from sqlalchemy.ext.declarative import declarative_base
from sqlalchemy import create_engine
#from sqlalchemy.pool import SingletonThreadPool
from datetime import datetime

import os

Base = declarative_base()

class  User(Base):


	__tablename__ = 'users'

	id = Column(Integer,primary_key=True)
	tg_id = Column(String)
	budget = Column(Integer,default=0)

	purchases = relationship("Expense",backref="user",lazy='dynamic')

	def add_to_balance(income):
		self.budget += int(income)

	def del_from_budget(expense):
		self.budget -= int(expense)

	def __init__(self, tg_id):
		self.tg_id = tg_id

	def __repr__(self):
		return '< User: {} >'.format(self.tg_id)

class Expense(Base):
	"""  """
	__tablename__ = 'expenses'

	id = Column(Integer,primary_key=True)
	name = Column(String)
	price = Column(Integer)
	purchase_type = Column(String)
	date = Column(DateTime, default=datetime.now)
	customer_id = Column(String, ForeignKey('users.tg_id'))

	def __init__(self,name,price,purchase_type):
		self.name = name
		self.price = price
		self.purchase_type = purchase_type

	def __repr__(self):
		return '< Expense: {}, {}, {} >'.format(self.name,self.price,self.customer_id)

engine = create_engine('postgres://{данные}',echo=True)

Base.metadata.create_all(engine)

ошибка:

spoiler

2020-02-06 20:49:18,809 INFO sqlalchemy.engine.base.Engine select version()
2020-02-06 20:49:18,809 INFO sqlalchemy.engine.base.Engine {}
2020-02-06 20:49:19,006 INFO sqlalchemy.engine.base.Engine select current_schema()
2020-02-06 20:49:19,007 INFO sqlalchemy.engine.base.Engine {}
2020-02-06 20:49:19,203 INFO sqlalchemy.engine.base.Engine SELECT CAST('test plain returns' AS VARCHAR(60)) AS anon_1
2020-02-06 20:49:19,203 INFO sqlalchemy.engine.base.Engine {}
2020-02-06 20:49:19,306 INFO sqlalchemy.engine.base.Engine SELECT CAST('test unicode returns' AS VARCHAR(60)) AS anon_1
2020-02-06 20:49:19,307 INFO sqlalchemy.engine.base.Engine {}
2020-02-06 20:49:19,407 INFO sqlalchemy.engine.base.Engine show standard_conforming_strings
2020-02-06 20:49:19,407 INFO sqlalchemy.engine.base.Engine {}
2020-02-06 20:49:19,621 INFO sqlalchemy.engine.base.Engine

CREATE TABLE users (
	id SERIAL NOT NULL, 
	tg_id VARCHAR, 
	budget INTEGER, 
	PRIMARY KEY (id)
)

2020-02-06 20:49:19,621 INFO sqlalchemy.engine.base.Engine {}
2020-02-06 20:49:19,829 INFO sqlalchemy.engine.base.Engine COMMIT
2020-02-06 20:49:19,929 INFO sqlalchemy.engine.base.Engine

CREATE TABLE expenses (
	id SERIAL NOT NULL, 
	name VARCHAR, 
	price INTEGER, 
	purchase_type VARCHAR, 
	date TIMESTAMP WITHOUT TIME ZONE, 
	customer_id VARCHAR, 
	PRIMARY KEY (id), 
	FOREIGN KEY(customer_id) REFERENCES users (tg_id)
)

2020-02-06 20:49:19,930 INFO sqlalchemy.engine.base.Engine {}
2020-02-06 20:49:20,163 INFO sqlalchemy.engine.base.Engine ROLLBACK
Traceback (most recent call last):
  File "C:\Users\User\Desktop\Python\TBot_Socks\venv\lib\site-packages\sqlalchemy\engine\base.py", line 1246, in _execute_context
    cursor, statement, parameters, context
  File "C:\Users\User\Desktop\Python\TBot_Socks\venv\lib\site-packages\sqlalchemy\engine\default.py", line 581, in do_execute
    cursor.execute(statement, parameters)
psycopg2.errors.InvalidForeignKey: there is no unique constraint matching given keys for referenced table "users"