{
  "id": "python/django-query-annotation-error",
  "signature": "django.core.exceptions.FieldError: Cannot compute Sum('price'): 'price' is an aggregate",
  "signature_zh": "字段错误：无法计算Sum('price')：'price'是聚合字段",
  "regex": "django\\.core\\.exceptions\\.FieldError:\\ Cannot\\ compute\\ Sum\\('price'\\):\\ 'price'\\ is\\ an\\ aggregate",
  "domain": "python",
  "category": "data_error",
  "subcategory": null,
  "root_cause": "对已聚合的字段再次进行聚合操作",
  "root_cause_type": "generic",
  "root_cause_zh": "在包含聚合的查询集中再次使用聚合函数，导致嵌套聚合错误",
  "versions": [
    {
      "version": "3.x",
      "introduced": null,
      "deprecated": null,
      "removed": null,
      "behavior_change": null,
      "status": "active"
    }
  ],
  "os_specific": {},
  "dead_ends": [
    {
      "action": "",
      "why_fails": "values()不会重置聚合状态",
      "fail_rate": 0.7,
      "condition": "",
      "sources": []
    },
    {
      "action": "",
      "why_fails": "aggregate返回字典而非查询集，可能不适用",
      "fail_rate": 0.6,
      "condition": "",
      "sources": []
    }
  ],
  "workarounds": [
    {
      "action": "",
      "success_rate": 0.9,
      "how": "qs.values('category').annotate(total=Sum('price'))",
      "condition": "",
      "sources": []
    },
    {
      "action": "",
      "success_rate": 0.85,
      "how": "from django.db.models import Subquery; ...",
      "condition": "",
      "sources": []
    }
  ],
  "workarounds_zh": [],
  "transition_graph": {
    "leads_to": [],
    "preceded_by": [],
    "frequently_confused_with": []
  },
  "official_doc_url": null,
  "official_doc_section": null,
  "error_code": null,
  "verification_tier": "ai_generated",
  "confidence": 0.82,
  "fix_success_rate": 0.8,
  "resolvable": "true",
  "first_seen": "2024-05-17",
  "last_confirmed": "2025-01-01",
  "last_updated": "2025-01-01",
  "evidence_count": 0,
  "tags": [],
  "locale": "en",
  "aliases": []
}