v2.2.0

Added

• Metadata filtering: New filter_by_metadata() method for efficient key-value filtering using SQLite's JSON_EXTRACT
• Metadata counting: New count_by_metadata() method to count records matching metadata filters
• Combined search: New similarity_search_with_filter() method combining vector similarity with metadata filtering
• Support for nested JSON paths in metadata filters (e.g., {"author.name": "Alice"})
• Pagination support in filter_by_metadata() with limit and offset parameters
• New validation function validate_metadata_filters() for secure filter validation
• New utility function build_metadata_where_clause() for safe SQL generation
• Comprehensive test coverage for metadata filtering (unit, integration, and security tests)
• New example advanced_metadata_queries.py demonstrating nested paths and complex queries
• Updated metadata_filtering.py example with new filtering methods
• Export/import functionality: New methods for data portability
  • export_to_json() - Export records to JSON Lines format
  • import_from_json() - Import records from JSON Lines format
  • export_to_csv() - Export records to CSV format
  • import_from_csv() - Import records from CSV format
• Support for filtered exports using metadata filters
• Batch processing for memory-efficient import/export of large datasets
• Optional embedding inclusion in exports
• New io module with import/export utilities
• Comprehensive tests for import/export functionality
• New example export_import_example.py demonstrating backup/restore workflows

Security

• SQL injection prevention in metadata filter keys
• Validation of JSON paths to prevent malicious queries
• Parameterized queries for all metadata filtering operations

Improved

• Data migration workflows now much easier
• Backup and restore capabilities for production use
• Interoperability with external systems via CSV/JSON

Documentation

• Added "Metadata Filtering" section to README with examples
• Added "Export/Import" section to README with examples
• Updated examples list in README
• Added comprehensive docstrings for new methods