# fastapi.exceptions.RequestValidationError: Field required: 'name'

- **ID:** `python/fastapi-request-body-missing`
- **Domain:** python
- **Category:** data_error
- **Verification:** ai_generated
- **Fix Rate:** 80%

## Root Cause

请求体中缺少Pydantic模型定义的必需字段

## Version Compatibility

| Version | Status | Introduced | Deprecated |
|---------|--------|------------|------------|
| 3.x | active | — | — |

## Workarounds

1. **在请求中包含所有必需字段** (95% success)
   ```
   {"name": "John", "age": 30}
   ```
2. **在模型中将字段设为可选并设置默认值** (90% success)
   ```
   class Item(BaseModel):
    name: str = 'default'
   ```

## Dead Ends

- **在路由函数中使用默认参数** — Pydantic模型验证在路由函数之前执行 (60% fail)
- **修改模型字段为可选但保留验证** — 字段变为可选后，缺少时不会报错但可能逻辑错误 (40% fail)