训练题单中章节的 ID 不能为 0 但可以为负
Author: Tiger-Coder-CCreated May 13, 2026Updated Aug 25, 2026
如附件图片，训练题单中章节的 _id 如果为 0 会提示 each node should have a _id，但可以为负。示例代码：
[
{
"_id": -1,
"title": "环境测试",
"requireNids": [],
"pids": [
1
]
}
]Source: hydro-dev/Hydro