FIX: Stored datetime.time values have the microseconds attribute set to zero

[Jahnvi Thakkar (jahnvi480)]

Work Item / Issue Reference

AB#38820

GitHub Issue: #203

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Summary

This pull request introduces significant improvements to how SQL TIME/TIME2 values are handled in the MSSQL Python driver, transitioning from native C-type bindings to text-based representations. The changes ensure correct parsing, binding, and conversion between SQL TIME values and Python datetime.time objects, addressing edge cases and improving compatibility.

SQL TIME/TIME2 Handling Improvements

• Changed TIME/TIME2 parameter binding in mssql_python/cursor.py to use SQL_TYPE_TIME and text C-types (SQL_C_CHAR), and normalized Python datetime.time values to ISO text format with microseconds.
• Updated C++ bindings in ddbc_bindings.cpp to bind and fetch TIME/TIME2 columns as text buffers instead of native structs, and introduced a robust parser (ParseSqlTimeTextToPythonObject) for converting SQL time text to Python objects.
• Adjusted row size calculations and buffer allocations for TIME/TIME2 columns to use the new maximum text length constant (SQL_TIME_TEXT_MAX_LEN).

Testing and Utilities

• Exposed the time-text parser as a test helper in the Python module, allowing for unit testing of TIME/TIME2 parsing edge cases.

Miscellaneous

• Improved table cleanup in tests by switching to drop_table_if_exists for reliability.

[Copilot]

Pull request overview

This PR fixes microsecond loss when round-tripping SQL Server TIME/TIME2 values by switching Python datetime.time binding to a text C-type with microsecond precision and updating the C++ fetch/batch-fetch paths to parse TIME2 from text back into datetime.time.

Changes:

• Bind Python datetime.time parameters as text (SQL_C_CHAR/SQL_C_WCHAR) using isoformat(timespec="microseconds").
• Fetch SQL_SS_TIME2 as text in both SQLGetData_wrap and batch fetch, converting to datetime.time via a new parser.
• Add a regression test asserting TIME(6) preserves microseconds on insert/select.

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 4 comments.

File	Description
tests/test_004_cursor.py	Adds a regression test for TIME microsecond round-trip; minor formatting updates to SQL strings.
mssql_python/pybind/ddbc_bindings.cpp	Adds a TIME text parser and changes SQL_SS_TIME2 retrieval/binding to use SQL_C_CHAR buffers.
mssql_python/cursor.py	Changes TIME parameter mapping and normalizes TIME values to microsecond ISO text in execute/executemany binding.

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[github-actions]

📊 Code Coverage Report

🔥 Diff Coverage 86%

🎯 Overall Coverage 78%

📈 Total Lines Covered:6636 out of 8408 📁 Project:mssql-python

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Diff Coverage

Diff: main...HEAD, staged and unstaged changes

• mssql_python/cursor.py (100%)
• mssql_python/pybind/ddbc_bindings.cpp (79.2%): Missing lines 3500-3503,3678

Summary

• Total: 36 lines
• Missing: 5 lines
• Coverage: 86%

mssql_python/pybind/ddbc_bindings.cpp

Lines 3496-3507

3496 row.append(PythonObjectCache::get_time_class()(
3497 t2.hour, t2.minute, t2.second, t2.fraction / 1000)); // ns to µs3498 } else {
3499if (!SQL_SUCCEEDED(ret)) {
! 3500LOG("SQLGetData: Error retrieving SQL_SS_TIME2 for column "
! 3501"%d - SQLRETURN=%d",
! 3502 i, ret);
! 3503 }
3504 row.append(py::none());
3505 }
3506break;
3507 }

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Lines 3674-3682

3674 #endif
3675default:
3676 std::ostringstream errorString;
3677 errorString << "Unsupported data type for column - " << columnName << ", Type - "
! 3678 << effectiveDataType << ", column ID - " << i;
3679LOG("SQLGetData: %s", errorString.str().c_str());
3680ThrowStdException(errorString.str());
3681break;
3682 }

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📋 Files Needing Attention

📉 Files with overall lowest coverage (click to expand)

mssql_python.pybind.logger_bridge.cpp: 59.2%
mssql_python.pybind.ddbc_bindings.h: 67.8%
mssql_python.row.py: 70.5%
mssql_python.pybind.logger_bridge.hpp: 70.8%
mssql_python.pybind.connection.connection.cpp: 75.3%
mssql_python.__init__.py: 77.3%
mssql_python.ddbc_bindings.py: 79.6%
mssql_python.pybind.connection.connection_pool.cpp: 79.6%
mssql_python.connection.py: 85.2%
mssql_python.cursor.py: 86.1%

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