FIX: Invalid data type for None by subrata-ms · Pull Request #332

FIX: Invalid data type for None by subrata-ms · Pull Request #332 · microsoft/mssql-python

AB#39794

GitHub Issue: #273

Summary

This pull request adds support for binding arrays of NULL parameters in SQL statements and introduces a corresponding test to ensure correct behavior when executing multiple inserts with only NULL values. The main focus is on handling the SQL_C_DEFAULT type for parameter arrays, ensuring all values are NULL, and verifying this functionality through unit testing.

Parameter binding improvements:

Added logic to BindParameterArray in ddbc_bindings.cpp to handle the SQL_C_DEFAULT type, ensuring that arrays of NULL values are properly bound and validated. If any non-NULL value is detected, an exception is thrown.

Testing enhancements:

Added a new test test_executemany_NONE_parameter_list in test_004_cursor.py to verify that executemany correctly inserts rows with all NULL values and that the count matches the expected number of inserts.

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November 17, 2025 14:44

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Pull Request Overview

This pull request fixes an issue with the data type mapping for NULL parameters in the _map_sql_type function. The change updates the C type for NULL parameters from SQL_C_DEFAULT (99) to SQL_C_CHAR (-8), which aligns with the SQL type SQL_VARCHAR that's also returned for NULL parameters.

Key changes:

Updated the C type for NULL parameters in _map_sql_type from SQL_C_DEFAULT to SQL_C_CHAR to match the SQL_VARCHAR SQL type being used

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📊 Code Coverage Report

🔥 Diff Coverage 93%	🎯 Overall Coverage 76%	📈 Total Lines Covered: `5379` out of `7037` 📁 Project: `mssql-python`

Diff Coverage

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

mssql_python/pybind/ddbc_bindings.cpp (93.3%): Missing lines 2465

Summary

Total: 15 lines
Missing: 1 line
Coverage: 93%

mssql_python/pybind/ddbc_bindings.cpp

Lines 2461-2469

  2461                     dataPtr = nullBuffer;
  2462                     bufferLength = 1;
  2463                     LOG("BindParameterArray: SQL_C_DEFAULT bound - param_index=%d", paramIndex);
  2464                     break;
! 2465                 }
  2466                 default: {
  2467                     LOG("BindParameterArray: Unsupported C type - "
  2468                         "param_index=%d, C_type=%d",
  2469                         paramIndex, info.paramCType);

📋 Files Needing Attention

📉 Files with overall lowest coverage (click to expand)

mssql_python.pybind.logger_bridge.hpp: 58.8%
mssql_python.pybind.logger_bridge.cpp: 59.2%
mssql_python.row.py: 66.2%
mssql_python.helpers.py: 67.5%
mssql_python.pybind.ddbc_bindings.cpp: 69.3%
mssql_python.pybind.connection.connection.cpp: 73.6%
mssql_python.ddbc_bindings.py: 79.6%
mssql_python.connection.py: 83.9%
mssql_python.cursor.py: 84.4%
mssql_python.__init__.py: 84.9%

Summary

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Pull Request Overview

📊 Code Coverage Report

🔥 Diff Coverage

93%

🎯 Overall Coverage

76%

Diff Coverage

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

Summary

mssql_python/pybind/ddbc_bindings.cpp

📋 Files Needing Attention

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