SQL Injection Vulnerability Scanner

Review this code for SQL injection vulnerabilities:

**Code:**
```{{LANGUAGE}}
{{CODE}}
```

**Framework/ORM:** {{FRAMEWORK}}
**Database System:** {{DATABASE_SYSTEM}}
**User Input Sources:** {{INPUT_SOURCES}}

Please provide:
1. Identification of all SQL injection vulnerabilities
2. Severity rating for each vulnerability
3. Attack vectors and exploitation examples
4. Secure code rewrites using:
   - Parameterized queries
   - Prepared statements
   - ORM methods
5. Input validation recommendations
6. Output encoding if applicable
7. Additional security layers
8. Testing for SQL injection
9. Security best practices checklist