alembic/env.py

from logging.config import fileConfig
from sqlalchemy import engine_from_config
from sqlalchemy import pool
from alembic import context
from app.config import settings
from app.db import Base
from app import models

config = context.config

if config.config_file_name is not None:
    fileConfig(config.config_file_name)

target_metadata = Base.metadata

def run_migrations_offline() -> None:
    url = settings.DIRECT_DATABASE_URL or settings.DATABASE_URL
    context.configure(
        url=url,
        target_metadata=target_metadata,
        literal_binds=True,
        dialect_opts={"paramstyle": "named"},
    )
    with context.begin_transaction():
        context.run_migrations()

def run_migrations_online() -> None:
    configuration = config.get_section(config.config_ini_section, {})
    configuration["sqlalchemy.url"] = settings.DIRECT_DATABASE_URL or settings.DATABASE_URL
    
    connectable = engine_from_config(
        configuration,
        prefix="sqlalchemy.",
        poolclass=pool.NullPool,
    )
    with connectable.connect() as connection:
        context.configure(
            connection=connection, target_metadata=target_metadata
        )
        with context.begin_transaction():
            context.run_migrations()

if context.is_offline_mode():
    run_migrations_offline()
else:
    run_migrations_online()