Error thrown when trying to insert a row where the PK is not explicitly defined as autoincrement=False and does not have a column_identity value

[reevery]

Hi

This has been bugging me for a while, but I only decided to look into this today.

I'm trying to insert a row into a table where the PK is a date. In my original schema, I had not defined autoincrement=False against this PK.

As a result, in get_lastrowid() in base.py, the first check autoincrement_pk_columns includes the PK column, so the return None is not executed at this stage. So, the function then goes on to find the column_identity column from exa_all_columns, which comes back Null.

As a result, the int(...) call is calling Null, and the exception is thrown.

The quick fix is to add a check of result[0] is None, and if so either throw a warning or error so that it's clear what the issue is, or ignore it and return None.

    session.commit()
  File "/usr/local/lib/python3.4/dist-packages/sqlalchemy/orm/session.py", line 921, in commit
    self.transaction.commit()
  File "/usr/local/lib/python3.4/dist-packages/sqlalchemy/orm/session.py", line 461, in commit
    self._prepare_impl()
  File "/usr/local/lib/python3.4/dist-packages/sqlalchemy/orm/session.py", line 441, in _prepare_impl
    self.session.flush()
  File "/usr/local/lib/python3.4/dist-packages/sqlalchemy/orm/session.py", line 2192, in flush
    self._flush(objects)
  File "/usr/local/lib/python3.4/dist-packages/sqlalchemy/orm/session.py", line 2312, in _flush
    transaction.rollback(_capture_exception=True)
  File "/usr/local/lib/python3.4/dist-packages/sqlalchemy/util/langhelpers.py", line 66, in __exit__
    compat.reraise(exc_type, exc_value, exc_tb)
  File "/usr/local/lib/python3.4/dist-packages/sqlalchemy/util/compat.py", line 187, in reraise
    raise value
  File "/usr/local/lib/python3.4/dist-packages/sqlalchemy/orm/session.py", line 2276, in _flush
    flush_context.execute()
  File "/usr/local/lib/python3.4/dist-packages/sqlalchemy/orm/unitofwork.py", line 389, in execute
    rec.execute(self)
  File "/usr/local/lib/python3.4/dist-packages/sqlalchemy/orm/unitofwork.py", line 548, in execute
    uow
  File "/usr/local/lib/python3.4/dist-packages/sqlalchemy/orm/persistence.py", line 181, in save_obj
    mapper, table, insert)
  File "/usr/local/lib/python3.4/dist-packages/sqlalchemy/orm/persistence.py", line 799, in _emit_insert_statements
    execute(statement, multiparams)
  File "/usr/local/lib/python3.4/dist-packages/sqlalchemy/engine/base.py", line 945, in execute
    return meth(self, multiparams, params)
  File "/usr/local/lib/python3.4/dist-packages/sqlalchemy/sql/elements.py", line 263, in _execute_on_connection
    return connection._execute_clauseelement(self, multiparams, params)
  File "/usr/local/lib/python3.4/dist-packages/sqlalchemy/engine/base.py", line 1053, in _execute_clauseelement
    compiled_sql, distilled_params
  File "/usr/local/lib/python3.4/dist-packages/sqlalchemy/engine/base.py", line 1202, in _execute_context
    result = context._setup_crud_result_proxy()
  File "/usr/local/lib/python3.4/dist-packages/sqlalchemy/engine/default.py", line 896, in _setup_crud_result_proxy
    self._setup_ins_pk_from_lastrowid()
  File "/usr/local/lib/python3.4/dist-packages/sqlalchemy/engine/default.py", line 932, in _setup_ins_pk_from_lastrowid
    lastrowid = self.get_lastrowid()
  File "/usr/local/lib/python3.4/dist-packages/sqlalchemy_exasol/base.py", line 327, in get_lastrowid
    return int(result[0]) - 1
TypeError: int() argument must be a string, a bytes-like object or a number, not 'NoneType'

[jank]

Thank you for digging out the details and root cause of your issue.
From what you write, throwing an exception sounds like a meaningful way to let the developer know what is going on (e.g. missing PK column).
Would you like to provide a pull request that fixes this issue for inclusion in next release?

[reevery]

I don't have it locally, so that's a lot of effort for potentially two lines of code, but if I ever fork it, then it will be top of my list.

[jank]

Closing this issue: not able to reproduce.