backend/migrations/env.py

from logging.config import fileConfig
from sqlalchemy import engine_from_config, pool
from alembic import context
import os, sys
config = context.config
if config.config_file_name is not None:
    fileConfig(config.config_file_name)
target_metadata = None
def run_migrations_offline():
    url = config.get_main_option("sqlalchemy.url")
    context.configure(url=url, literal_binds=True)
    with context.begin_transaction():
        context.run_migrations()
def run_migrations_online():
    connectable = engine_from_config(config.get_section(config.config_ini_section), prefix="sqlalchemy.", poolclass=pool.NullPool)
    with connectable.connect() as connection:
        context.configure(connection=connection)
        with context.begin_transaction():
            context.run_migrations()
if context.is_offline_mode():
    run_migrations_offline()
else:
    run_migrations_online()