Bug Report: featchall() throws TypeError, when query result returns no rows

[Diadochokinetic]

• Operating System Name: Ubuntu 22.04

• db2level output from clidriver if in use: DB21085I This instance or install (instance name, where applicable:
  "db2inst1") uses "64" bits and DB2 code release "SQL12010" with level
  identifier "02010110".
  Informational tokens are "DB2 v12.1.0.0", "special_50594",
  "DYN2411071022AMD64_50594", and Fix Pack "0".
  Product is installed at "/opt/ibm/db2/V12.1".

• Target Db2 Server Version: DB2 v12.1.0.0

• Python Version: 3.10.15

• ibm_db version: 3.2.7

• For non-Windows, output of below commands:
  uname: Linux
  uname -m: x86_64

• Value of below environment variables if set:
  IBM_DB_HOME: /home/db2inst1/sqllib
  PATH: /home/db2inst1/miniforge-pypy3/envs/pandas-db2/bin:/home/db2inst1/miniforge-pypy3/condabin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games:/snap/bin:/home/db2inst1/sqllib/bin:/home/db2inst1/sqllib/adm:/home/db2inst1/sqllib/misc:/home/db2inst1/sqllib/pd:/home/db2inst1/sqllib/gskit/bin:/home/db2inst1/sqllib/db2tss/bin
  LIB/LD_LIBRARY_PATH/DYLD_LIBRARY_PATH:

• Test script to reproduce the problem.

• For installation related issue, complete output of pip install ibm_db command.

Steps to Reproduce:

from sqlalchemy import create_engine, text
db2 = create_engine("ibm_db_sa://db2inst1:password@localhost:25000/sample")
with db2.begin() as conn:
    result = conn.execute(text("SELECT CID FROM DB2INST1.CUSTOMER WHERE CID > 2000"))
    print(result.fetchall())

In versions below 3.2.7, e.g. 3.2.6 the print shows an empty list, which is the expected result. In version 3.2.7 the execution yields the follow exception:

---------------------------------------------------------------------------
TypeError                                 Traceback (most recent call last)
Cell In[4], line 3
      1 with db2.begin() as conn:
      2     result = conn.execute(text("SELECT CID FROM DB2INST1.CUSTOMER WHERE CID > 2000"))
----> 3     print(result.fetchall())

File [~/miniforge-pypy3/envs/pandas-db2/lib/python3.10/site-packages/sqlalchemy/engine/result.py:1317](http://127.0.0.1:8888/lab/tree/Projects/miniforge-pypy3/envs/pandas-db2/lib/python3.10/site-packages/sqlalchemy/engine/result.py#line=1316), in Result.fetchall(self)
   1314 def fetchall(self) -> Sequence[Row[_TP]]:
   1315     """A synonym for the :meth:`_engine.Result.all` method."""
-> 1317     return self._allrows()

File [~/miniforge-pypy3/envs/pandas-db2/lib/python3.10/site-packages/sqlalchemy/engine/result.py:551](http://127.0.0.1:8888/lab/tree/Projects/miniforge-pypy3/envs/pandas-db2/lib/python3.10/site-packages/sqlalchemy/engine/result.py#line=550), in ResultInternal._allrows(self)
    549 made_rows: List[_InterimRowType[_R]]
    550 if make_row:
--> 551     made_rows = [make_row(row) for row in rows]
    552 else:
    553     made_rows = rows  # type: ignore

TypeError: 'NoneType' object is not iterable

[bchoudhary6415]

Hello @Diadochokinetic,

Thank you for bringing up this issue.
A fix has already been provided in PR #1028, and it will be included in the next release of the python ibm_db package. Once the update is available, this issue should no longer occur.

Thanks again for reporting it!