blocks|key|201015|text|那些发现这个问题的人，OP在原始问题下面的评论中提到了这个问题的解决方案是：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|201016|records.set('Name',+'test')|code-block|syntax|javascript|201017|这将添加一个名为Name的新属性，其值为test。|offset|length|style|CODE|201018|entityMap^0|0|0|8|4|K|4|0^^$0|@$1|2|3|4|5|6|7|O|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|P|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|Q|8|@$I|R|J|S|K|L]|$I|T|J|U|K|L]]|9|@]|A|$]]|$1|M|3|-4|5|6|7|V|8|@]|9|@]|A|$]]]|N|$]]

Those finding this problem, OP mentioned in a comment below the original question that the solution for this problem is:

<pre><code>records.set('Name', 'test')
</code></pre>

This adds a new attribute called <code>Name</code> having value <code>test</code>.

blocks|key|3040540|text|我假设您正在尝试将属性添加到返回的Mongoose文档中，以便在其他地方重用它。Mongoose返回的文档不是直接的JSON对象，您需要将其转换为对象以向其添加属性。下面的代码应该可以工作：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|3040541|//...+record+is+a+mongoose+Document
var+r+=+record.toObject();
r.Name+=+'test';
console.log("Record+",r);|code-block|syntax|javascript|3040542|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

I am assuming you are trying to add a property to a returned Mongoose Document to reuse it somewhere else. Documents returned by Mongoose are not JSON objects directly, you'll need to convert them to an object to add properties to them. The following should work:

<pre><code>//... record is a mongoose Document
var r = record.toObject();
r.Name = 'test';
console.log("Record ",r);
</code></pre>

blocks|key|198528|text|只需使用|type|unstyled|depth|inlineStyleRanges|entityRanges|data|198529|var+convertedJSON+=+JSON.parse(JSON.stringify(mongooseReturnedDocument);|code-block|syntax|javascript|198530|然后,|198531|convertedJSON.newProperty+=+'Hello!'+|198532|“你好！”可以是任何值、数字、对象或JSON对象文字。|198533|干杯！:)|198534|entityMap^0|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|Q|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|R|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|S|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|T|8|@]|9|@]|A|$E|F]]|$1|K|3|L|5|6|7|U|8|@]|9|@]|A|$]]|$1|M|3|N|5|6|7|V|8|@]|9|@]|A|$]]|$1|O|3|-4|5|6|7|W|8|@]|9|@]|A|$]]]|P|$]]

Just use,

<pre><code>var convertedJSON = JSON.parse(JSON.stringify(mongooseReturnedDocument);
</code></pre>

and Then,

<pre><code>convertedJSON.newProperty = 'Hello!' 
</code></pre>

'Hello!' can be anything, a number, a object or JSON Object Literal.

Cheers! :)

blocks|key|201045|text|我经历了类似的问题，并希望我的几个小时的存在挫折能帮助处于同样情况的其他人。我倾向于相信通过Mongoose返回的文档是只读的。这其实不是真的。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|201046|但是，不能将不在架构中的属性分配给文档。|201047|因此，除非您的模式具有以下内容：|201048|{
++++Name:+{String}
}|code-block|syntax|javascript|201049|尝试为文档指定名称时，您会经常感到沮丧。|201050|现在，上面的答案中有一些解决方法也适用于我，但它们没有找到问题的根源：|201051|myDocument.toObject();
JSON.parse(JSON.stringify(myDocument);|201052|这些将会起作用，但在我看来，它们只是隐藏了问题。真正的问题是，Mongoose比我们认识到的更聪明，它正在执行您的模式，这是它应该做的。|201053|entityMap^0|0|0|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|U|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|V|8|@]|9|@]|A|$]]|$1|D|3|E|5|6|7|W|8|@]|9|@]|A|$]]|$1|F|3|G|5|H|7|X|8|@]|9|@]|A|$I|J]]|$1|K|3|L|5|6|7|Y|8|@]|9|@]|A|$]]|$1|M|3|N|5|6|7|Z|8|@]|9|@]|A|$]]|$1|O|3|P|5|H|7|10|8|@]|9|@]|A|$I|J]]|$1|Q|3|R|5|6|7|11|8|@]|9|@]|A|$]]|$1|S|3|-4|5|6|7|12|8|@]|9|@]|A|$]]]|T|$]]

I experienced a similar problem, and hope that my hours of existential frustration help others in the same situation. My inclination was to believe that documents returned via Mongoose are read-only. This is actually not true. 

However, you cannot assign a property to your document that is not also in your Schema. 

So, unless your schema has the following: 

<pre><code>{
 Name: {String}
}
</code></pre>

you will be constantly frustrated by trying to assign Name to your document.

Now, there are workarounds in the answers above that also worked for me, but they do not get to the root of the problem:

<pre><code>myDocument.toObject();
JSON.parse(JSON.stringify(myDocument);
</code></pre>

These will work, but in my opinion they just hide the problem. The real issue is that Mongoose is smarter than we realized and is enforcing your schema, as it should.

blocks|key|201055|text|您也可以使用lean()方法，例如const+users+=+await+Users.find().lean().exec()|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|201056|来自mongoose文档：|201057|启用了lean选项的查询返回的|201058|文档是纯javascript对象，而不是MongooseDocuments。它们没有保存方法、getters/setters或其他Mongoose魔法应用的|blockquote|201059|201060|entityMap|0|LINK|mutability|MUTABLE|url|http://mongoosejs.com/docs/api.html#query_Query-lean^0|H|1A|6|6|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|V|8|@$9|W|A|X|B|C]]|D|@$9|Y|A|Z|1|10]]|E|$]]|$1|F|3|G|5|6|7|11|8|@]|D|@]|E|$]]|$1|H|3|I|5|6|7|12|8|@]|D|@]|E|$]]|$1|J|3|K|5|L|7|13|8|@]|D|@]|E|$]]|$1|M|3|-4|5|6|7|14|8|@]|D|@]|E|$]]|$1|N|3|-4|5|6|7|15|8|@]|D|@]|E|$]]]|O|$P|$5|Q|R|S|E|$T|U]]]]

You could also use the <a href="http://mongoosejs.com/docs/api.html#query_Query-lean" rel="nofollow noreferrer">lean()</a> method, e.g. <code>const users = await Users.find().lean().exec()</code>

From the mongoose documentation:

<blockquote>
 Documents returned from queries with the lean option enabled are plain
 javascript objects, not MongooseDocuments. They have no save method,
 getters/setters or other Mongoose magic applied
</blockquote>

blocks|key|198548|text|我的变种。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|198549|如果使用{strict:false}定义模式，则只需通过以下方式添加新属性|offset|length|style|CODE|198550|recorcd.newProp+=+'newvalue';|198551|如果使用{strict:true}定义模式，您可以像前面提到的那样将Mongoose对象转换为对象，也可以使用命令|198552|record.set('newProp','newValue',{strict:false})|198553|请参阅http://mongoosejs.com/docs/api.html#document_Document-schema|198554|entityMap|0|LINK|mutability|MUTABLE|url|http://mongoosejs.com/docs/api.html#document_Document-schema^0|0|4|E|0|0|T|0|4|D|0|0|1B|0|3|1O|0|0^^$0|@$1|2|3|4|5|6|7|X|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|Y|8|@$D|Z|E|10|F|G]]|9|@]|A|$]]|$1|H|3|I|5|6|7|11|8|@$D|12|E|13|F|G]]|9|@]|A|$]]|$1|J|3|K|5|6|7|14|8|@$D|15|E|16|F|G]]|9|@]|A|$]]|$1|L|3|M|5|6|7|17|8|@$D|18|E|19|F|G]]|9|@]|A|$]]|$1|N|3|O|5|6|7|1A|8|@]|9|@$D|1B|E|1C|1|1D]]|A|$]]|$1|P|3|-4|5|6|7|1E|8|@]|9|@]|A|$]]]|Q|$R|$5|S|T|U|A|$V|W]]]]

My variant.

If schema defined with <code>{strict:false}</code> you can simply add new property by

<code>
recorcd.newProp = 'newvalue';
</code>

If schema defined with <code>{strict:true}</code> you can either convert Mongoose object to object as mentioned earlier or use command

<code>
record.set('newProp','newValue',{strict:false})
</code>

See <a href="http://mongoosejs.com/docs/api.html#document_Document-schema" rel="nofollow noreferrer">http://mongoosejs.com/docs/api.html#document_Document-schema</a>

blocks|key|2827709|text|如果您已将此对象加载到records中，则records.Name+=+"test"或records['Name']+=+"test"都可以工作。您没有正确加载对象，或者正在向其中插入未定义的值。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|2827710|要测试:添加测试，这应该打印‘console.log(records.userId)’到终端。|2827711|还要添加console.log(name)。如果你得到了ReferenceError:+name+is+not+defined，你显然不能这样做：records.Name+=+name|2827712|entityMap^0|B|7|L|L|17|O|0|F|R|0|4|H|S|Z|21|J|0^^$0|@$1|2|3|4|5|6|7|L|8|@$9|M|A|N|B|C]|$9|O|A|P|B|C]|$9|Q|A|R|B|C]]|D|@]|E|$]]|$1|F|3|G|5|6|7|S|8|@$9|T|A|U|B|C]]|D|@]|E|$]]|$1|H|3|I|5|6|7|V|8|@$9|W|A|X|B|C]|$9|Y|A|Z|B|C]|$9|10|A|11|B|C]]|D|@]|E|$]]|$1|J|3|-4|5|6|7|12|8|@]|D|@]|E|$]]]|K|$]]

If you have loaded this object into <code>records</code>, both <code>records.Name = "test"</code> or <code>records['Name'] = "test"</code> will work. You have either not loaded the object correctly, or are inserting an undefined value into it.

To test: add <code>console.log(records.userId)</code>, this should print 'test' to the terminal.

Also add <code>console.log(name)</code>. If you get <code>ReferenceError: name is not defined</code>, you obviously cannot do: <code>records.Name = name</code>

I have an object like this

<pre><code>==================records=========={ Id: 5114a3c21203e0d811000088,
 userId: 'test',
 sUserId: test,
 userName: 'test',
 url: 'test',
 Title: 'test'
}
</code></pre>

I need to add a new field Name : 'test' to the above record, I tried giving records.Name = name, it didn't work.

Helps please

Thanks,
Prats

Add a new attribute to existing json object in node.js

JSON

我有一个这样的对象==================records=========={ Id: 5114a3c21203e0d811000088,  userId: 'test',  sUserId: test,  userName: 'test',  url: 'test',  Title: 'test'}我需要添加一个新的字段名：‘’到上面的记录中，我试着给出records.Name =，

问向node.js中的现有json对象添加新属性
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回答 7

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