Alembic Autogenerate Creates Redundant Foreign Key Migrations for MySQL Database

Question

I'm using Alembic (1.1.3) with SQLAlchemy and MySQL (5.7) in a Python (3.9) project to manage database migrations. Despite no changes to my ORM models or the database schema, every time I run alembic revision --autogenerate, the generated migration script includes redundant operations to drop and then recreate the same foreign key constraints, creating 100+ more rows that are deleting foreign keys and adding them again.

I am using single schema in my DB.

i saw `alembic revision --autogenerate` produces redundant foreign key migrations and tried to implement it but still no luck and it did not solve my issue.

I have made sure all the points made in that questions are not happening for me and still i am getting redundent migrations added.

• Not directly naming any db schemas in my sqlalchemy classes (always table_name.id, not schema_name.table_name.id)
• I tried adding the solution that sifts through all availabe schemas (include_scemas=true) with all the relevant parameters, it skipped the db schema i was referencing and instead went through all the other schemas and just outputted empty migration
• made sure my Base is using declarative correctly.

for example removing and adding foreign keys :

example model :

class Company(Base):
    __tablename__ = 'company'

    id = Column(Integer, primary_key=True, autoincrement=True)
    created_at = Column(DateTime, default=datetime.datetime.now)
    updated_at = Column(DateTime, default=datetime.datetime.now)
    organization_id = Column(Integer, ForeignKey('organization.id'))
    owner_id = Column(Integer, ForeignKey("users.id"))
    name = Column(String(255))
    slug = Column(String(255))
    website = Column(String(255))
    description = Column(String(255))
    active_templates = relationship("ActiveTemplate", back_populates="company")
    branches = relationship("Branch", back_populates="company")

my baseClass

from sqlalchemy import Integer, Column, MetaData
from sqlalchemy.ext.declarative import as_declarative, declared_attr

# # Define the naming convention
# convention = {
#     "ix": "ix_%(column_0_label)s",
#     "uq": "uq_%(table_name)s_%(column_0_name)s",
#     "ck": "ck_%(table_name)s_%(constraint_name)s",
#     "fk": "fk_%(table_name)s_%(column_0_name)s_%(referred_table_name)s",
#     "pk": "pk_%(table_name)s"
# }
#
# # Apply the naming convention to the MetaData instance
# metadata = MetaData(naming_convention=convention)

@as_declarative()
class Base:
    id: Column(Integer, primary_key=True, autoincrement=True)
    __name__: str
    # Generate __tablename__ automatically

    @declared_attr
    def __tablename__(cls) -> str:
        return cls.__name__.lower()

    def to_dict(self):
        """returns a dictionary representation of the object"""
        return {c.name: getattr(self, c.name) for c in self.__table__.columns}

    op.drop_index('fk_company_1_idx', table_name='company')
    op.drop_constraint('fk_company_1', 'company', type_='foreignkey')
    op.drop_constraint('company_ibfk_1', 'company', type_='foreignkey')
    op.create_foreign_key(None, 'company', 'users', ['owner_id'], ['id'])
    op.create_foreign_key(None, 'company', 'organization', ['organization_id'], ['id'])

my env.py

from __future__ import with_statement

import os
import sys
from alembic import context
from sqlalchemy import engine_from_config, pool
from logging.config import fileConfig
from dotenv import load_dotenv


load_dotenv()

# this is the Alembic Config object, which provides
# access to the values within the .ini file in use.
config = context.config

# Interpret the config file for Python logging.
# This line sets up loggers basically.
fileConfig(config.config_file_name)

# add your model's MetaData object here
# for 'autogenerate' support
# from myapp import mymodel
# target_metadata = mymodel.Base.metadata
# target_metadata = None


sys.path = ['', '..'] + sys.path[1:] # noqa
from app.db.base import * # noqa
from app.db.base_class import Base  # noqa

target_metadata = Base.metadata

# other values from the config, defined by the needs of env.py,
# can be acquired:
# my_important_option = config.get_main_option("my_important_option")
# ... etc.


def get_url():
    user = os.getenv("DB_USER")
    password = os.getenv("DB_PASSWORD")
    server = os.getenv("DB_HOST")
    db = os.getenv("DB_NAME")
    port = str(os.getenv("PORT"))
    return f"mysql+mysqlconnector://{user}:{password}@{server}:{port}/{db}"


def run_migrations_offline():
    """Run migrations in 'offline' mode.

    This configures the context with just a URL
    and not an Engine, though an Engine is acceptable
    here as well.  By skipping the Engine creation
    we don't even need a DBAPI to be available.

    Calls to context.execute() here emit the given string to the
    script output.

    """
    url = get_url()
    context.configure(
        url=url, target_metadata=target_metadata, literal_binds=True, compare_type=True
    )

    with context.begin_transaction():
        context.run_migrations()


def run_migrations_online():
    """Run migrations in 'online' mode.

    In this scenario we need to create an Engine
    and associate a connection with the context.

    """
    configuration = config.get_section(config.config_ini_section)
    configuration["sqlalchemy.url"] = get_url()
    connectable = engine_from_config(
        configuration,
        prefix="sqlalchemy.",
        poolclass=pool.NullPool,
    )

    with connectable.connect() as connection:
        context.configure(
            connection=connection,
            target_metadata=target_metadata,
            compare_type=True,
        )

        with context.begin_transaction():
            context.run_migrations()


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

i will appriciate any help im totally not sure how to solve this now. 


tried running alembic autogenerate and i keep getting redundent field names that are added to the migration.