无法在Postgresql sqlalchemy中创建表

Question

I am trying to create a few tables in sqlalchemy database using Python. The tables are not getting created in the database and I can't find anything in the logging information.

Model.py

from sqlalchemy.ext.declarative import declarative_base
Model = declarative_base()

Department.py [I have more models and all of them imports the Model.py, but I can't see any of these tables in my database]

from sqlalchemy import Column, Integer, String
from models.Model import Model

class Department(Model):
    __tablename__ = "department"
    oid = Column('oid', Integer, primary_key=True)
    name = Column('name', String, unique=True)

data_service_provider.py This class creates the engine. I am calling this class from the below script.

from models.InitDB import init_database from sqlalchemy import create_engine from sqlalchemy.orm import sessionmaker from models.Model import Model import logging

class DataProviderService():
    def __init__(self, engine):
        logging.basicConfig()
        logging.getLogger('sqlalchemy.engine').setLevel(logging.DEBUG)
        if not engine:
            raise ValueError('The values specified in engine is not supported')
        self.engine = engine
        db_engine = create_engine(engine, echo=True)
        Model.metadata.create_all(db_engine)

middleware.py

from sqlalchemy.engine.url import URL
from config import settings
from data_provider_service import DataProviderService

db_engine = URL(**settings.DATABASE);

DATA_PROVIDER = DataProviderService(db_engine)

Settings.py

DATABASE = {
    'drivername': 'postgresql',
    'host': 'localhost',
    'port': '5432',
    'username': 'postgres',
    'password': 'punitjain',
    'database': 'csuf'
}

So basically Model.py is the base class which gets imported by all my model classes. In the data_service_provider.py I am creating the database engine and creating the tables. The middleware.py scripts make the database URL from Settings.py and call the DataProviderService.

I am trying for last few hours but the tables are not getting created. I can't find any useful information in the debug logs.

Following are the debug logs:

postgresql://postgres:password@localhost:5432/csuf
2018-02-13 04:17:55,496 INFO sqlalchemy.engine.base.Engine select version()
2018-02-13 04:17:55,496 INFO sqlalchemy.engine.base.Engine {}
2018-02-13 04:17:55,497 INFO sqlalchemy.engine.base.Engine select 
current_schema()
2018-02-13 04:17:55,497 INFO sqlalchemy.engine.base.Engine {}
2018-02-13 04:17:55,498 INFO sqlalchemy.engine.base.Engine SELECT CAST('test 
plain returns' AS VARCHAR(60)) AS anon_1
2018-02-13 04:17:55,499 INFO sqlalchemy.engine.base.Engine {}
INFO:sqlalchemy.engine.base.Engine:select version()
2018-02-13 04:17:55,499 INFO sqlalchemy.engine.base.Engine SELECT CAST('test 
unicode returns' AS VARCHAR(60)) AS anon_1
INFO:sqlalchemy.engine.base.Engine:{}
INFO:sqlalchemy.engine.base.Engine:select current_schema()
INFO:sqlalchemy.engine.base.Engine:{}
INFO:sqlalchemy.engine.base.Engine:SELECT CAST('test plain returns' AS 
VARCHAR(60)) AS anon_1
INFO:sqlalchemy.engine.base.Engine:{}
INFO:sqlalchemy.engine.base.Engine:SELECT CAST('test unicode returns' AS 
VARCHAR(60)) AS anon_1
2018-02-13 04:17:55,500 INFO sqlalchemy.engine.base.Engine {}
INFO:sqlalchemy.engine.base.Engine:{}
2018-02-13 04:17:55,500 INFO sqlalchemy.engine.base.Engine show 
standard_conforming_strings
INFO:sqlalchemy.engine.base.Engine:show standard_conforming_strings
2018-02-13 04:17:55,500 INFO sqlalchemy.engine.base.Engine {}
INFO:sqlalchemy.engine.base.Engine:{}

Answer 1

I moved all my models into a different package but missed to add init.py which was causing issues. Adding init.py and specifying the model names into that resolved it. Thanks!

init.py

__all__ = ["College", "Course", "Department", "Program", "init_database"]

from models.College import College
from models.Course import Course
from models.Department import Department
from models.Program import Program