FEAT: Adding Cursor.connection attribute

[jahnvi480]

Work Item / Issue Reference

AB#34891

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Summary

This pull request introduces the DB-API 2.0-compliant connection attribute to the Cursor class in mssql_python, ensuring that each cursor exposes a read-only reference to its parent connection. The implementation is thoroughly tested with new and updated test cases covering polymorphic code, multi-cursor scenarios, connection lifecycle, and transaction control.

DB-API 2.0 compliance and attribute exposure

• Added a read-only connection property to the Cursor class, exposing the connection object used to create the cursor, and updated internal usage to store the connection as a private attribute (_connection). (mssql_python/cursor.py) [1] [2]

Internal refactoring

• Refactored internal references from self.connection to self._connection to enforce encapsulation and ensure the public attribute is read-only. (mssql_python/cursor.py)

Test coverage for the new attribute

• Added comprehensive tests to verify the existence, correctness, and read-only nature of the cursor.connection attribute, including multi-cursor and multi-connection environments, accessibility after cursor/connection closure, and polymorphic code examples. (tests/test_004_cursor.py)

Transaction and polymorphic usage examples

• Added tests demonstrating transaction control and polymorphic code patterns using the new cursor.connection attribute, confirming correct behavior in real-world scenarios. (tests/test_004_cursor.py)