{
  "id": "python/sqlalchemy-integrity-error-duplicate",
  "signature": "sqlalchemy.exc.IntegrityError: (psycopg2.errors.UniqueViolation) duplicate key value violates unique constraint \"users_email_key\"",
  "signature_zh": "sqlalchemy.exc.IntegrityError：(psycopg2.errors.UniqueViolation) 重复键值违反唯一约束 \"users_email_key\"",
  "regex": "sqlalchemy\\.exc\\.IntegrityError:\\ \\(psycopg2\\.errors\\.UniqueViolation\\)\\ duplicate\\ key\\ value\\ violates\\ unique\\ constraint\\ \"users_email_key\"",
  "domain": "python",
  "category": "data_error",
  "subcategory": null,
  "root_cause": "Inserting a record with a duplicate value in a unique column.",
  "root_cause_type": "generic",
  "root_cause_zh": "在唯一列中插入重复值。",
  "versions": [
    {
      "version": "3.x",
      "introduced": null,
      "deprecated": null,
      "removed": null,
      "behavior_change": null,
      "status": "active"
    }
  ],
  "os_specific": {},
  "dead_ends": [
    {
      "action": "Catching exception and ignoring without rollback.",
      "why_fails": "Transaction remains in aborted state; subsequent queries fail.",
      "fail_rate": 0.9,
      "condition": "",
      "sources": []
    },
    {
      "action": "Using session.merge() without checking for conflicts.",
      "why_fails": "Merge may still raise IntegrityError if primary key conflicts.",
      "fail_rate": 0.6,
      "condition": "",
      "sources": []
    }
  ],
  "workarounds": [
    {
      "action": "Check for existing record before insert.",
      "success_rate": 0.95,
      "how": "existing = session.query(User).filter_by(email='test@example.com').first()\nif not existing:\n    session.add(User(email='test@example.com'))\nsession.commit()",
      "condition": "",
      "sources": []
    },
    {
      "action": "Use ON CONFLICT DO NOTHING via SQLAlchemy dialect.",
      "success_rate": 0.9,
      "how": "from sqlalchemy.dialects.postgresql import insert\nstmt = insert(User).values(email='test@example.com').on_conflict_do_nothing()\nsession.execute(stmt)\nsession.commit()",
      "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": "2024-05-12",
  "last_confirmed": "2025-01-01",
  "last_updated": "2025-01-01",
  "evidence_count": 0,
  "tags": [],
  "locale": "en",
  "aliases": []
}