{
  "id": "python/sqlalchemy-orm-session-merge-error",
  "signature": "sqlalchemy.orm.exc.UnmappedInstanceError: Class 'builtins.dict' is not mapped",
  "signature_zh": "sqlalchemy.orm.exc.UnmappedInstanceError：类 'builtins.dict' 未映射",
  "regex": "sqlalchemy\\.orm\\.exc\\.UnmappedInstanceError:\\ Class\\ 'builtins\\.dict'\\ is\\ not\\ mapped",
  "domain": "python",
  "category": "runtime_error",
  "subcategory": null,
  "root_cause": "Passing a dictionary instead of a mapped class instance to session.merge().",
  "root_cause_type": "generic",
  "root_cause_zh": "向 session.merge() 传递字典而不是映射类实例。",
  "versions": [
    {
      "version": "3.x",
      "introduced": null,
      "deprecated": null,
      "removed": null,
      "behavior_change": null,
      "status": "active"
    }
  ],
  "os_specific": {},
  "dead_ends": [
    {
      "action": "Converting dict to object manually without proper mapping.",
      "why_fails": "Object still not recognized by ORM.",
      "fail_rate": 0.8,
      "condition": "",
      "sources": []
    },
    {
      "action": "Using session.add() with dict.",
      "why_fails": "Same error; session expects mapped instances.",
      "fail_rate": 0.9,
      "condition": "",
      "sources": []
    }
  ],
  "workarounds": [
    {
      "action": "Create mapped instance from dict.",
      "success_rate": 0.95,
      "how": "user_data = {'id': 1, 'name': 'Alice'}\nuser = User(**user_data)\nmerged_user = session.merge(user)",
      "condition": "",
      "sources": []
    },
    {
      "action": "Use session.execute() with insert statement.",
      "success_rate": 0.9,
      "how": "from sqlalchemy import insert\nstmt = insert(User).values(**user_data)\nsession.execute(stmt)",
      "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": 0.85,
  "fix_success_rate": 0.8,
  "resolvable": "true",
  "first_seen": "2025-10-05",
  "last_confirmed": "2025-01-01",
  "last_updated": "2025-01-01",
  "evidence_count": 0,
  "tags": [],
  "locale": "en",
  "aliases": []
}