SQLAlchemy - Good practice to make life easy

sqlalchemy-practice.md

Make a Custom JSON Encoder/Serializer

A example of custom json serializer:

# file: json.py
def custom_json_encoder(o):
    if isinstance(o, pydantic.BaseModel):
        res = o.dict()
        return res['__root__'] if '__root__' in res else res
    return pydantic_encoder(o)


def dumps(obj, **kwargs):
    return json.dumps(obj, default=custom_json_encoder, **kwargs)

Bind it to the db engine:

create_async_engine(self.url, json_serializer=json.dumps, **engine_options)

Let Alembic get sqlalchemy.url from main App Config

1. Disable sqlalchemy.url setting in alembic.ini.

2. In alembic/env.py, something like:

   from myproj.conf import settings
   import myproj.models
   
   dbc = settings.db
   
   config = context.config
   config.set_main_option(
       'sqlalchemy.url',
       f'postgresql+psycopg2://{dbc.user}:{dbc.password}@{dbc.host}:{dbc.port}/{dbc.database}'
   )