Integrate SQLAlchemy ORM- V2 #456

[tatianaborda]

#🚀 Pull Request Description

Description

This pull request integrates SQLAlchemy ORM into the StarkFinder project as requested in issue #456. The implementation provides a complete database integration solution with connection pooling, comprehensive CRUD operations, and establishes foundational infrastructure for future database-related features.

Specifically, it addresses the following:

• SQLAlchemy Integration: Complete setup of SQLAlchemy ORM with proper configuration for both SQLite (development/testing) and PostgreSQL (production) databases.

• Database Connection Pool: Implemented robust connection pooling with proper session management, error handling, and cleanup mechanisms.

• User Model Implementation:

  • Comprehensive User model with all essential fields (id, username, email, is_active, timestamps)
  • Proper relationships and constraints defined
  • SQLAlchemy best practices followed

• Repository Pattern: Full UserRepository implementation providing:

  • Create operations with data validation
  • Read operations (by ID, get all, with filtering capabilities)
  • Update operations with data integrity checks
  • Delete operations with proper cleanup
  • Error handling for all database operations

• Alembic Migrations: Complete migration system setup for database schema management and version control.

• Comprehensive Testing Suite:

  • 100% test coverage for all CRUD operations
  • Database fixtures and proper test isolation
  • Integration tests for connection management
  • Error handling and edge case validation

• Foundation for Future Issues: This implementation establishes the complete infrastructure needed for issues Write Tests for Contract CRUD Operations #475 (Contract CRUD tests) and Test GET /user Endpoint #477 (User endpoint tests), providing reusable patterns and tested database integration.

🔗 Linked Issues

Fixes #456

Type of change

• New feature (non-breaking change which adds functionality)
• Chore (refactoring, dependency updates, etc.)

How Has This Been Tested?

• Unit Tests: Complete test suite for all CRUD operations with individual method testing
• Integration Tests: Database connection, session management, and model interactions verified
• Tested locally with full stack setup: Verified with both SQLite and PostgreSQL configurations

Test Results:

✅ Database connection and session management
✅ User CREATE operations with validation
✅ User READ operations (by ID, get all, filtering)  
✅ User UPDATE operations with data integrity
✅ User DELETE operations with proper cleanup
✅ Error handling and edge cases
✅ All tests passing with 100% success rate

Test Configuration:

• SQLite in-memory database for fast test execution
• PostgreSQL compatibility verified
• Proper test isolation and cleanup between tests
• Mock data fixtures for consistent testing
• Environment-based configuration for different setups

📸 Screenshots

No UI changes - Backend database integration only

✅ PR Checklist

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes
• Any dependent changes have been merged and published in downstream modules
• I have tested these changes locally
• Relevant documentation is updated
• My code follows the repository's coding guidelines
• I have added/updated tests that prove my fix/feature
• No breaking changes introduced
• Code is well-commented and readable

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Project	Deployment	Preview	Comments	Updated (UTC)
stark-finder-mq45	Ready	Preview	Comment	Sep 1, 2025 7:05pm

[PoulavBhowmick03]

@tatianaborda it has merge conflicts. please fix and tag @tosoham

[tatianaborda]

@tatianaborda it has merge conflicts. please fix and tag @tosoham
Oh! It hadn't merge conflicts yesterday :(
ok I'm going to checkit again

[tatianaborda]

Hi @tosoham can you check this PR please?

[tosoham]

LGTM