Database Query Builder API Designer

Design a query builder API for this use case:

**Target Database:** {{DATABASE}}
**Programming Language:** {{LANGUAGE}}
**Query Types Needed:** {{QUERY_TYPES}}
**Type Safety Requirements:** {{TYPE_SAFETY}}
**Existing ORM/Framework:** {{ORM}}

Please provide:
1. Query builder interface design
2. Fluent API method chaining
3. Type-safe implementations for:
   - SELECT with column picking
   - WHERE conditions
   - JOINs
   - Aggregations
   - Subqueries
4. SQL injection prevention
5. Query execution and result mapping
6. Transaction support
7. Usage examples
8. Testing strategy
9. Performance considerations
10. Extension points