FIX: Fixed and Added tests for Type Inference Bug (#252)

### Work Item / Issue Reference <!-- IMPORTANT: Please follow the PR template guidelines below. For mssql-python maintainers: Insert your ADO Work Item ID below (e.g. AB#37452) For external contributors: Insert Github Issue number below (e.g. #149) Only one reference is required - either GitHub issue OR ADO Work Item. --> <!-- mssql-python maintainers: ADO Work Item --> > AB#<WORK_ITEM_ID> <!-- External contributors: GitHub Issue --> > GitHub Issue: #253 ------------------------------------------------------------------- ### Summary <!-- Insert your summary of changes below. Minimum 10 characters required. --> This pull request removes the `_select_best_sample_value` static method and updates how sample values are selected for type inference in the `executemany` method. Instead of using the old method, the code now relies on `_compute_column_type` to determine sample values and type information. **Refactoring and Type Inference Updates:** * Removed the `_select_best_sample_value` static method from `cursor.py`, consolidating the logic for type inference. * Updated the `executemany` method to use `_compute_column_type` for determining sample values, minimum, and maximum values for each column, improving clarity and maintainability. <!-- ### PR Title Guide > For feature requests FEAT: (short-description) > For non-feature requests like test case updates, config updates , dependency updates etc CHORE: (short-description) > For Fix requests FIX: (short-description) > For doc update requests DOC: (short-description) > For Formatting, indentation, or styling update STYLE: (short-description) > For Refactor, without any feature changes REFACTOR: (short-description) > For release related changes, without any feature changes RELEASE: #<RELEASE_VERSION> (short-description) ### Contribution Guidelines External contributors: - Create a GitHub issue first: https://github.com/microsoft/mssql-python/issues/new - Link the GitHub issue in the "GitHub Issue" section above - Follow the PR title format and provide a meaningful summary mssql-python maintainers: - Create an ADO Work Item following internal processes - Link the ADO Work Item in the "ADO Work Item" section above - Follow the PR title format and provide a meaningful summary -->

Author: gargsaumya

mssql_python/cursor.py

@@ -1613,6 +1613,7 @@ def executemany(self, operation: str, seq_of_parameters: list) -> None:
  # Use auto-detection for columns without explicit types
  column = [row[col_index] for row in seq_of_parameters] if hasattr(seq_of_parameters, '__getitem__') else []
  sample_value, min_val, max_val = self._compute_column_type(column)
+
  dummy_row = list(sample_row)
  paraminfo = self._create_parameter_types_list(
  sample_value, param_info, dummy_row, col_index, min_val=min_val, max_val=max_val

tests/test_004_cursor.py

@@ -1262,6 +1262,118 @@ def test_executemany_binary_data_edge_cases(cursor, db_connection):
  cursor.execute("DROP TABLE IF EXISTS #pytest_binary_test")
  db_connection.commit()
 
+def test_executemany_mixed_ints(cursor, db_connection):
+ """Test executemany with mixed positive and negative integers."""
+ try:
+ cursor.execute("CREATE TABLE #pytest_mixed_ints (val INT)")
+ data = [(1,), (-5,), (3,)]
+ cursor.executemany("INSERT INTO #pytest_mixed_ints VALUES (?)", data)
+ db_connection.commit()
+
+ cursor.execute("SELECT val FROM #pytest_mixed_ints ORDER BY val")
+ results = [row[0] for row in cursor.fetchall()]
+ assert sorted(results) == [-5, 1, 3]
+ finally:
+ cursor.execute("DROP TABLE IF EXISTS #pytest_mixed_ints")
+ db_connection.commit()
+
+
+def test_executemany_int_edge_cases(cursor, db_connection):
+ """Test executemany with very large and very small integers."""
+ try:
+ cursor.execute("CREATE TABLE #pytest_int_edges (val BIGINT)")
+ data = [(0,), (2**31-1,), (-2**31,), (2**63-1,), (-2**63,)]
+ cursor.executemany("INSERT INTO #pytest_int_edges VALUES (?)", data)
+ db_connection.commit()
+
+ cursor.execute("SELECT val FROM #pytest_int_edges ORDER BY val")
+ results = [row[0] for row in cursor.fetchall()]
+ assert results == sorted([0, 2**31-1, -2**31, 2**63-1, -2**63])
+ finally:
+ cursor.execute("DROP TABLE IF EXISTS #pytest_int_edges")
+ db_connection.commit()
+
+
+def test_executemany_bools_and_ints(cursor, db_connection):
+ """Test executemany with mix of booleans and integers."""
+ try:
+ cursor.execute("CREATE TABLE #pytest_bool_int (val INT)")
+ data = [(True,), (False,), (2,)]
+ cursor.executemany("INSERT INTO #pytest_bool_int VALUES (?)", data)
+ db_connection.commit()
+
+ cursor.execute("SELECT val FROM #pytest_bool_int ORDER BY val")
+ results = [row[0] for row in cursor.fetchall()]
+ # True -> 1, False -> 0
+ assert results == [0, 1, 2]
+ finally:
+ cursor.execute("DROP TABLE IF EXISTS #pytest_bool_int")
+ db_connection.commit()
+
+
+def test_executemany_ints_with_none(cursor, db_connection):
+ """Test executemany with integers and None values."""
+ try:
+ cursor.execute("CREATE TABLE #pytest_int_none (val INT)")
+ data = [(1,), (None,), (3,)]
+ cursor.executemany("INSERT INTO #pytest_int_none VALUES (?)", data)
+ db_connection.commit()
+
+ cursor.execute("SELECT val FROM #pytest_int_none ORDER BY val")
+ results = [row[0] for row in cursor.fetchall()]
+ assert results.count(None) == 1
+ assert results.count(1) == 1
+ assert results.count(3) == 1
+ finally:
+ cursor.execute("DROP TABLE IF EXISTS #pytest_int_none")
+ db_connection.commit()
+
+
+def test_executemany_strings_of_various_lengths(cursor, db_connection):
+ """Test executemany with strings of different lengths."""
+ try:
+ cursor.execute("CREATE TABLE #pytest_varied_strings (val NVARCHAR(50))")
+ data = [("a",), ("abcd",), ("abc",)]
+ cursor.executemany("INSERT INTO #pytest_varied_strings VALUES (?)", data)
+ db_connection.commit()
+
+ cursor.execute("SELECT val FROM #pytest_varied_strings ORDER BY val")
+ results = [row[0] for row in cursor.fetchall()]
+ assert sorted(results) == ["a", "abc", "abcd"]
+ finally:
+ cursor.execute("DROP TABLE IF EXISTS #pytest_varied_strings")
+ db_connection.commit()
+
+
+def test_executemany_bytes_values(cursor, db_connection):
+ """Test executemany with bytes values."""
+ try:
+ cursor.execute("CREATE TABLE #pytest_bytes (val VARBINARY(50))")
+ data = [(b"a",), (b"abcdef",)]
+ cursor.executemany("INSERT INTO #pytest_bytes VALUES (?)", data)
+ db_connection.commit()
+
+ cursor.execute("SELECT val FROM #pytest_bytes ORDER BY val")
+ results = [row[0] for row in cursor.fetchall()]
+ assert results == [b"a", b"abcdef"]
+ finally:
+ cursor.execute("DROP TABLE IF EXISTS #pytest_bytes")
+ db_connection.commit()
+
+def test_executemany_empty_parameter_list(cursor, db_connection):
+ """Test executemany with an empty parameter list."""
+ try:
+ cursor.execute("CREATE TABLE #pytest_empty_params (val INT)")
+ data = []
+ cursor.executemany("INSERT INTO #pytest_empty_params VALUES (?)", data)
+ db_connection.commit()
+
+ cursor.execute("SELECT COUNT(*) FROM #pytest_empty_params")
+ count = cursor.fetchone()[0]
+ assert count == 0
+ finally:
+ cursor.execute("DROP TABLE IF EXISTS #pytest_empty_params")
+ db_connection.commit()
 
 def test_nextset(cursor):
  """Test nextset"""