queries

Aggregation performs database-level calculations efficiently. I use aggregate() for single results across entire queryset (like average or total) and annotate() to add calculated fields to each object. Common aggregates include Count, Sum, Avg, Min, a

Q objects enable complex query logic with OR, AND, and NOT operations. I combine them with | for OR and & for AND. The ~Q() syntax negates a condition. This is cleaner than raw SQL for dynamic filters. I build Q objects conditionally based on user