execute_stream does not remove empty lines with comment only resulting in error: Empty SQL statement.

Python version

Python 3.10.0 (default, Mar 3 2022, 03:57:21) [Clang 12.0.0 ]

Operating system and processor architecture

macOS-10.16-x86_64-i386-64bit

Installed packages

annotated-types==0.7.0
anyio==4.8.0
asn1crypto==1.5.1
atpublic==5.0
backports.tarfile==1.2.0
black==24.10.0
certifi==2024.12.14
cffi==1.17.1
cfgv==3.4.0
chardet==5.2.0
charset-normalizer==3.4.1
click==8.1.7
cloudpickle==2.2.1
coverage==7.6.10
cryptography==44.0.0
diff_cover==9.2.1
distlib==0.3.9
exceptiongroup==1.2.2
factory_boy==3.3.1
Faker==33.1.0
filelock==3.16.1
gitdb==4.0.12
GitPython==3.1.43
h11==0.14.0
hatch==1.14.0
hatchling==1.27.0
httpcore==1.0.7
httpx==0.28.1
hyperlink==21.0.0
identify==2.6.5
idna==3.10
importlib_metadata==8.5.0
iniconfig==2.0.0
jaraco.classes==3.4.0
jaraco.context==6.0.1
jaraco.functools==4.1.0
Jinja2==3.1.5
jinja2schema==0.1.4
keyring==25.6.0
markdown-it-py==3.0.0
MarkupSafe==3.0.2
mdurl==0.1.2
more-itertools==10.5.0
mypy==1.14.1
mypy-extensions==1.0.0
nodeenv==1.9.1
packaging==24.2
pathspec==0.12.1
pexpect==4.9.0
platformdirs==4.3.6
pluggy==1.5.0
pre_commit==4.0.1
protobuf==5.29.2
ptyprocess==0.7.0
pycparser==2.22
pydantic==2.9.2
pydantic_core==2.23.4
Pygments==2.19.1
PyJWT==2.10.1
pyOpenSSL==24.3.0
pytest==8.3.4
pytest-cov==6.0.0
pytest-randomly==3.16.0
python-dateutil==2.9.0.post0
pytz==2024.2
PyYAML==6.0.2
requests==2.32.3
requirements-parser==0.11.0
rich==13.9.4
shellingham==1.5.4
six==1.17.0
smmap==5.0.2
sniffio==1.3.1
-e git+ssh://git@github.com/snowflakedb/snowflake-cli.git@8cc48be4534a5531b9ff6f4a82aebdc891e94239#egg=snowflake_cli
snowflake-connector-python==3.12.4
snowflake-snowpark-python==1.25.0
snowflake.core==1.0.2
sortedcontainers==2.4.0
syrupy==4.8.0
tomli==2.2.1
tomli_w==1.1.0
tomlkit==0.13.2
trove-classifiers==2025.1.7.14
typer==0.12.5
types-setuptools==75.6.0.20241223
typing_extensions==4.12.2
tzlocal==5.2
urllib3==2.2.3
userpath==1.9.2
uv==0.5.16
virtualenv==20.28.1
zipp==3.21.0
zstandard==0.23.0

What did you do?

Try this stream with execute_stream() in connection.py:

-- middle comment;
select 1;  select 2; -- comment ; still comment
-- extra comment;
-- extra comment2;"

Basically anything with a comment at the end of the stream will cause this error:

Empty SQL statement.

If you look closely at the code, it seems that the issue is in split_statements() call, which is resulting in:

[('-- middle comment;\nselect 1;', False), ('select 2; -- comment ; still comment', False), ('-- extra comment;\n-- extra comment2;', None)]

It splits the statements correctly, except that the last statement is not really a statement as it includes comments only.

What did you expect to see?

Expected for the code to execute successfully.

Can you set logging to DEBUG and collect the logs?

import logging
import os

for logger_name in ('snowflake.connector',):
    logger = logging.getLogger(logger_name)
    logger.setLevel(logging.DEBUG)
    ch = logging.StreamHandler()
    ch.setLevel(logging.DEBUG)
    ch.setFormatter(logging.Formatter('%(asctime)s - %(threadName)s %(filename)s:%(lineno)d - %(funcName)s() - %(levelname)s - %(message)s'))
    logger.addHandler(ch)