Unit Test Failure: AssertionError due to error message capitalization mismatch in `test_prepare.py`

[setoru]

Description:
When executing the test case tests/test_prepare.py::TestPrepare::test_prepare_02, an AssertionError is thrown. The error occurs because the expected error message "Column "a" does not exist." does not match the actual error message "column "a" does not exist".

Logs:

async_gaussdb.exceptions.UndefinedColumnError: Column "a" does not exist.
During handling of the above exception, another exception occurred:
Traceback (most recent call last):
  File "/usr/lib64/python3.9/unittest/case.py", line 59, in testPartExecutor
    yield
  File "/usr/lib64/python3.9/unittest/case.py", line 592, in run
    self._callTestMethod(testMethod)
  File "/usr/lib64/python3.9/unittest/case.py", line 550, in _callTestMethod
    method()
  File "/home/gaussdbuser/gaussdb-python-async/.venv/lib64/python3.9/site-packages/async_gaussdb/_testbase/__init__.py", line 92, in wrapper
    self.loop.run_until_complete(coro)
  File "/usr/lib64/python3.9/asyncio/base_events.py", line 642, in run_until_complete
    return future.result()
  File "/home/gaussdbuser/gaussdb-python-async/tests/test_prepare.py", line 35, in test_prepare_02
    await self.con.prepare('SELECT a')
  File "/usr/lib64/python3.9/unittest/case.py", line 239, in __exit__
    self._raiseFailure("{}" does not match "{}".format,
  File "/usr/lib64/python3.9/unittest/case.py", line 163, in _raiseFailure
    raise self.failureException(msg)
AssertionError: "column "a" does not exist" does not match "Column "a" does not exist."

How to reproduce it:

pytest --durations=0 -s -v tests/test_prepare.py::TestPrepare::test_prepare_02

Expected Behavior
Test pass.

Actual Behavior
The test fails with an AssertionError due to a mismatch in the error message capitalization ("column" vs "Column").

Environment

• OS: Huawei Cloud EulerOS 2.0
• Python Version: 3.9
• Database: GaussDB Kernel 505.2.1.SPC0800 build 3e43b3bc

[zhanghaitao3]

Title: Column Case Sensitivity Issue in GaussDB/OpenGauss Integration

Description:

We're encountering a case sensitivity issue with column names when running tests against GaussDB/OpenGauss. The error messages show different capitalization patterns:

• GaussDB error: Column "a" does not exist. (capital "C")

• OpenGauss error: column "a" does not exist. (lowercase "c")

Current Status:
We've already implemented case-insensitive exception matching to handle this discrepancy, but I wanted to document this behavior for future reference.

Technical Details:
This appears to be a difference in how GaussDB and OpenGauss format their error messages. While both databases are case-insensitive for column names in queries, their error message formatting differs.

Workaround:
We're currently using case-insensitive regex matching for these errors, for example:

with self.assertRaisesRegex(SomeException, r'(?i)column "a" does not exist'):
    # test code