SQLAlchemy Continuum tries to add empty rows to the database#342

SQLAlchemy Continuum tries to add an empty row to the database, when I try to update an existing record: ``` uow.process_before_flush(session) File "/project/.venv/lib/python3.11/site-packages/sqlalchemy_continuum/unit_of_work.py", line 71, in process_before_flush self.create_transaction(session) File "/project/.venv/lib/python3.11/site-packages/sqlalchemy_continuum/unit_of_work.py", line 121, in create_transaction ..... sqlalchemy.exc.IntegrityError: (pymysql.err.IntegrityError) (1048, "Column 'active' cannot be null") [SQL: INSERT INTO transactions (account_id, user_id, date, offset_iban, offset_name, offset_bic, final_party, amount, currency, description, hash, correction_transaction_id, correction_type, active) VALUES (%(account_id)s, %(user_id)s, %(date)s, %(offset_iban)s, %(offset_name)s, %(offset_bic)s, %(final_party)s, %(amount)s, %(currency)s, %(description)s, %(hash)s, %(correction_transaction_id)s, %(correction_type)s, %(active)s) RETURNING transactions.id, transactions.created_on, transactions.updated_on] [parameters: {'account_id': None, 'user_id': None, 'date': None, 'offset_iban': None, 'offset_name': None, 'offset_bic': None, 'final_party': None, 'amount': None, 'currency': None, 'description': None, 'hash': None, 'correction_transaction_id': None, 'correction_type': None, 'active': None}] ``` This is the code: ```python transaction = db.query(Transaction).filter(Transaction.id == transaction_id).first() transaction.active = False db.commit() ``` I've changed my models, so the active column can't hold a default value anymore, so now it fails. If I enable the active column to have a default value, then it updates the existing record, but it also adds an empty row to both the version table as well as the actual table which contains the transactions. I've no clue why this is happening. This is my database.py: ``` python from sqlalchemy import URL, create_engine from sqlalchemy.orm import declarative_base, sessionmaker from config import Settings from sqlalchemy_continuum import make_versioned settings = Settings() make_versioned(options={ 'transaction_column_name': 'tx_id', 'end_transaction_column_name': 'end_tx_id' }) mysql_db = { "drivername": "mysql+pymysql", "username": username, "password": .password, "host": host, "database": name, "port": port, "query": None, } engine = create_engine(URL.create(**mysql_db)) Base = declarative_base() Session = sessionmaker(engine, autoflush=False) def get_db(): db = Session() try: yield db finally: db.close() ``` I use `declarative_base()` instead of `configure_mappers`. Tables are created and rows are inserted in the version tables, so that should be all good. The only issue is the empty rows which are added when updating an existing row. The version table gets two rows inserted: one with the update that happened and an empty row telling an insert happened. At first, I thought the inserts were an issue, but then I figured actual empty rows were inserted in the transactions table. Now I get an error because I refuse the active column of having a default value. If I change my model by telling the active column can contain a default value, empty rows are inserted. Any thoughts?