FIX: Invalid data type for None

[subrata-ms]

AB#39794

GitHub Issue: #273

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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.

[Copilot]

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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[github-actions]

📊 Code Coverage Report

🔥 Diff Coverage 78%

🎯 Overall Coverage 77%

📈 Total Lines Covered: 5081 out of 6555 📁 Project: mssql-python

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Diff Coverage

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

• mssql_python/pybind/ddbc_bindings.cpp (78.9%): Missing lines 2193-2195,2212

Summary

• Total: 19 lines
• Missing: 4 lines
• Coverage: 78%

mssql_python/pybind/ddbc_bindings.cpp

Lines 2189-2199

  2189                     
  2190                     // Verify all values are indeed NULL
  2191                     for (size_t i = 0; i < paramSetSize; ++i) {
  2192                         if (!columnValues[i].is_none()) {
! 2193                             LOG("BindParameterArray: SQL_C_DEFAULT non-NULL value detected - param_index=%d, row=%zu", paramIndex, i);
! 2194                             ThrowStdException("SQL_C_DEFAULT (99) should only be used for NULL parameters at index " + std::to_string(paramIndex));
! 2195                         }
  2196                     }
  2197                     
  2198                     // For NULL parameters, we need to allocate a minimal buffer and set all indicators to SQL_NULL_DATA
  2199                     // Use SQL_C_CHAR as a safe default C type for NULL values

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Lines 2208-2216

  2208                     dataPtr = nullBuffer;
  2209                     bufferLength = 1;
  2210                     LOG("BindParameterArray: SQL_C_DEFAULT bound - param_index=%d, all_null=true", paramIndex);
  2211                     break;
! 2212                 }
  2213                 default: {
  2214                     LOG("BindParameterArray: Unsupported C type - param_index=%d, C_type=%d", paramIndex, info.paramCType);
  2215                     ThrowStdException("BindParameterArray: Unsupported C type: " + std::to_string(info.paramCType));
  2216                 }

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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.helpers.py: 66.6%
mssql_python.row.py: 67.4%
mssql_python.pybind.ddbc_bindings.cpp: 70.4%
mssql_python.pybind.connection.connection.cpp: 76.3%
mssql_python.ddbc_bindings.py: 79.6%
mssql_python.pybind.connection.connection_pool.cpp: 79.6%
mssql_python.pybind.ddbc_bindings.h: 79.7%
mssql_python.connection.py: 82.5%
mssql_python.cursor.py: 83.7%

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