Mongoose 无法更新数组：未定义的错误

Question

请看这段代码：

// Update route
router.put("/:comment_id", function (req, res) {
    Campground.findOneAndUpdate(
        {"_id": req.params.id, "comments._id": req.params.comment_id },
        {"$set": {"comments.$.text": req.body.comment.text}},
        function (err, campground) {
            if (err) {
                console.log("campground: " + campground); //logs campground: undefined
                console.log("comment id: " + req.params.comment_id); // logs comment id: 5a5f2ab0a6dccd210c0136de
                console.log("campground id: " + req.params.id); // logs campground id: 5a5e083af62da603900ab0d4
                res.redirect("/campgrounds");
            } else {
                res.redirect("/campgrounds/" + campground._id);
            }
        }
    );
});

ids 指的是这样的 url：

http://localhost:4000/campgrounds/5a5e083af62da603900ab0d4/comments/5a5e0845f62da603900ab0d5/edit

这对我来说很奇怪，为什么我无法联系到campground？这样我就无法更新我需要的文档。请帮助我找到解决方案。

编辑：console.log(err); 提供的错误：

{ CastError: Cast to ObjectId failed for value "secondo me no" at path "comments"
    at new CastError (folder\node_modules\mongoose\lib\error\cast.js:27:11)
    at ObjectId.cast (folder\node_modules\mongoose\lib\schema\objectid.js:158:13)
    at ObjectId.SchemaType.applySetters (folder\node_modules\mongoose\lib\schematype.js:695:12)
    at ObjectId.SchemaType._castForQuery (folder\node_modules\mongoose\lib\schematype.js:1066:15)
    at ObjectId.castForQuery (folder\node_modules\mongoose\lib\schema\objectid.js:198:15)
    at ObjectId.SchemaType.castForQueryWrapper (folder\node_modules\mongoose\lib\schematype.js:1035:15)
    at castUpdateVal (folder\node_modules\mongoose\lib\services\query\castUpdate.js:345:19)
    at walkUpdatePath (folder\node_modules\mongoose\lib\services\query\castUpdate.js:229:22)
    at castUpdate (folder\node_modules\mongoose\lib\services\query\castUpdate.js:72:18)
    at model.Query._castUpdate (folder\node_modules\mongoose\lib\query.js:2991:10)
    at castDoc (folder\node_modules\mongoose\lib\query.js:3017:18)
    at model.Query.Query._findAndModify (folder\node_modules\mongoose\lib\query.js:2292:19)
    at model.Query.Query._findOneAndUpdate (folder\node_modules\mongoose\lib\query.js:2139:8)
    at folder\node_modules\kareem\index.js:276:8
    at folder\node_modules\kareem\index.js:23:7
    at _combinedTickCallback (internal/process/next_tick.js:131:7)
  message: 'Cast to ObjectId failed for value "secondo me no" at path "comments"',
  name: 'CastError',
  stringValue: '"secondo me no"',
  kind: 'ObjectId',
  value: 'secondo me no',
  path: 'comments',
  reason: undefined }

@Younel 这是编辑视图：

<% include ../partials/header %>
<div class="container">
    <div class="row">
        <h1 style="text-align: center;">Edit Comment</h1>
        <div style="width: 30%; margin:25px auto;">
            <form action="/campgrounds/<%= campground_id %>/comments/<%= comment._id %>?_method=PUT" method="POST">
                <div class="form-group">
                    <input class="form-control" type="text" name="comment[text]" value="<%= comment.text %>">
                </div>
                <div class="form-group">
                    <button class="btn btn-lg btn-primary btn-block">Submit!</button>
                </div>
            </form>
            <a href="/campgrounds">Go Back</a>
        </div>
    </div>
</div>
<% include ../partials/footer %>

“secondo me no”是comment[text] 值

这是一个 github 仓库：https://github.com/ufollettu/YelpCamp.git（运行 v10/app.js）

Answer 1

如果我得到your models 正确，comments 不仅仅是一个数组，而是一个embedded documents 的数组，所以更新必须是这样的：

Campground.findById(req.params.id, function(err, doc) {
    if (err || !doc) {
        ...
    }
    const comment = doc.comments.id(req.params.comment_id);
    if (!comment) {
        ...
    }
    comment.text = req.body.comment.text;
    doc.save(function (err) {
        if (err) {
            ...
        }
    })
})

对于参考文件：

router.put("/:comment_id", function (req, res) {
    Comment.findOneAndUpdate(
        {"_id": req.params.comment_id},
        {"$set": {"text": req.body.comment.text}},
        function (err, comment) {
            if (err) {
                ...
            } 
            res.redirect("/campgrounds/" + req.params.id);
        }
    );
});