{
  "id": "python/fastapi-pydantic-v1-v2-migration-error",
  "signature": "pydantic.errors.PydanticUserError: `orm_mode` is deprecated. Use `from_attributes` instead.",
  "signature_zh": "pydantic.errors.PydanticUserError: `orm_mode` 已弃用，请使用 `from_attributes`。",
  "regex": "pydantic\\.errors\\.PydanticUserError:\\ `orm_mode`\\ is\\ deprecated\\.\\ Use\\ `from_attributes`\\ instead\\.",
  "domain": "python",
  "category": "config_error",
  "subcategory": null,
  "root_cause": "Code written for Pydantic v1 (`class Config: orm_mode = True`) runs under Pydantic v2, which renamed the setting.",
  "root_cause_type": "generic",
  "root_cause_zh": "为 Pydantic v1 编写的代码（`class Config: orm_mode = True`）在 Pydantic v2 下运行，而 v2 重命名了该设置。",
  "versions": [
    {
      "version": "2.x",
      "introduced": null,
      "deprecated": null,
      "removed": null,
      "behavior_change": null,
      "status": "active"
    }
  ],
  "os_specific": {},
  "dead_ends": [
    {
      "action": "",
      "why_fails": "FastAPI 0.100+ requires Pydantic v2; pip resolver errors.",
      "fail_rate": 0.9,
      "condition": "",
      "sources": []
    },
    {
      "action": "",
      "why_fails": "Config is ignored; from_orm/validation fails at runtime.",
      "fail_rate": 0.85,
      "condition": "",
      "sources": []
    }
  ],
  "workarounds": [
    {
      "action": "",
      "success_rate": 0.95,
      "how": "class UserOut(BaseModel):\n    model_config = ConfigDict(from_attributes=True)\n    id: int\n    name: str",
      "condition": "",
      "sources": []
    },
    {
      "action": "",
      "success_rate": 0.85,
      "how": "Run `bump-pydantic` codemod: `pip install bump-pydantic && bump-pydantic .` to auto-migrate.",
      "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": 0.88,
  "fix_success_rate": 0.8,
  "resolvable": "true",
  "first_seen": "2025-10-22",
  "last_confirmed": "2025-01-01",
  "last_updated": "2025-01-01",
  "evidence_count": 0,
  "tags": [],
  "locale": "en",
  "aliases": []
}