# SQLAlchemy 操作错误：数据库被锁定。

- **ID:** `python/flask-sqlalchemy-database-lock`
- **领域:** python
- **类别:** data_error
- **验证级别:** ai_generated
- **修复率:** 80%

## 根因

由于 Flask 应用中的并发写入或未提交事务，SQLite 数据库被锁定。

## 版本兼容性

| 版本 | 状态 | 引入 | 弃用 |
|------|------|------|------|
| 3.x | active | — | — |

## 解决方案

1. **** (80% 成功率)
   ```
   Set SQLite timeout: engine = create_engine('sqlite:///app.db', connect_args={'timeout': 30})
   ```
2. **** (90% 成功率)
   ```
   Use WAL mode: with engine.connect() as conn:
    conn.execute("PRAGMA journal_mode=WAL")
   ```

## 无效尝试

- **** — Timeout only waits for lock release; if transaction never commits, it still fails. (70% 失败率)
- **** — Uncommitted sessions hold locks; need explicit commit or rollback. (80% 失败率)