TypeError: Cannot use 'in' operator to search for '_id' in one

Question

我正在尝试使用 POST 请求来检索提交的按钮的值，并在呈现新页面和传递该值之前使用返回的值创建一个新的 Mongoose 模型条目。

当我尝试创建新的 "Type" 时，尽管收到类型错误： "TypeError: Cannot use 'in' operator to search for '_id' in one"。谁能帮我找出导致错误的原因以及如何解决它？

使用的表格：

       <form action="/round/type" method="POST" class="form-inline">
            <div class="row">
                <div class="col">
                    <button class="btn btn-lg btn-primary btn-block" name="roundType" value="one" type="submit">one</button>
                </div>
                <div class="col">
                    <button class="btn btn-lg btn-primary btn-block" name="roundType" value="two" type="submit">two</button>
                </div>
                <div class="col">
                    <button class="btn btn-lg btn-primary btn-block" name="roundType" value="three" type="submit">three</button>
                </div>
                <div class="col">
                    <button class="btn btn-lg btn-primary btn-block" name="roundType" value="four" type="submit">four</button>
                </div>
            </div>    
        </form>

模型架构：

var mongoose    = require("mongoose");

//Schema Setup  
var TypeSchema = new mongoose.Schema({
    roundType: String,
});

module.exports = mongoose.model("Type", TypeSchema);

Post请求：

router.post("/type", function(req, res){
    console.log(req.body.roundType); //this console.log prints the correct value submitted
    Type.create(req.body.roundType, function(err, newType){
        if(err){
            console.log(err);
        } else{
            res.redirect("/round/group", {roundType: newType}); 
        }
    });
});

错误信息：

TypeError: Cannot use 'in' operator to search for '_id' in one

at model.Document.$__buildDoc (/home/ubuntu/workspace/GolfSite_V2/node_modules/mongoose/lib/document.js:222:27)
at model.Document (/home/ubuntu/workspace/GolfSite_V2/node_modules/mongoose/lib/document.js:67:20)
at model.Model (/home/ubuntu/workspace/GolfSite_V2/node_modules/mongoose/lib/model.js:55:12)
at new model (/home/ubuntu/workspace/GolfSite_V2/node_modules/mongoose/lib/model.js:3867:13)
at /home/ubuntu/workspace/GolfSite_V2/node_modules/mongoose/lib/model.js:2035:51
at /home/ubuntu/workspace/GolfSite_V2/node_modules/async/internal/parallel.js:27:9
at eachOfArrayLike (/home/ubuntu/workspace/GolfSite_V2/node_modules/async/eachOf.js:57:9)
at exports.default (/home/ubuntu/workspace/GolfSite_V2/node_modules/async/eachOf.js:9:5)
at _parallel (/home/ubuntu/workspace/GolfSite_V2/node_modules/async/internal/parallel.js:26:5)
at parallelLimit (/home/ubuntu/workspace/GolfSite_V2/node_modules/async/parallel.js:85:26)
at /home/ubuntu/workspace/GolfSite_V2/node_modules/mongoose/lib/model.js:2056:5
at new Promise.ES6 (/home/ubuntu/workspace/GolfSite_V2/node_modules/mongoose/lib/promise.js:45:3)
at Function.create (/home/ubuntu/workspace/GolfSite_V2/node_modules/mongoose/lib/model.js:2019:17)
at /home/ubuntu/workspace/GolfSite_V2/routes/round.js:40:10
at Layer.handle [as handle_request] (/home/ubuntu/workspace/GolfSite_V2/node_modules/express/lib/router/layer.js:95:5)
at next (/home/ubuntu/workspace/GolfSite_V2/node_modules/express/lib/router/route.js:137:13)

Answer 1

Model.create 需要一个文档或文档数组作为第一个参数。目前，您只是从 POST 传递一个字符串值。

您的代码应如下所示：

Type.create({roundType: req.body.roundType}, function(err, newType){
    // ...
})

in 运算符检查对象中是否存在属性。例如：

let obj = {foo: 'bar'}
console.log('foo' in obj) // true

在这种情况下，它试图在字符串 one 中找到属性 _id - MongoDB 用作文档的唯一标识符。它不能这样做，所以抛出错误。

TypeError: Cannot use 'in' operator to search for '_id' in one

TypeError: Cannot use 'in' operator to search for '_id' in one

html

post

mongodb

node.js

mongoose-schema