FIX: Fixed and Added tests for Type Inference Bug

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"""