db.collection.update(  { _id:...} , { $set: { some_key : new_info  } } 

to

db.collection.update( { _id: ..} , { $set: { some_key: { param1: newValue} } } ); 

希望这对你有所帮助!

我尝试了findmodify()来更新一个预先存在的对象中的特定字段。

https://docs.mongodb.com/manual/reference/method/db.collection.findAndModify/

您应该考虑交换地更新对象，然后简单地将对象与更新后的字段存储在一起。如下所示

function update(_id) {
    return new Promise((resolve, reject) => {

        ObjModel.findOne({_id}).exec((err, obj) => {

            if(err) return reject(err)

            obj = updateObject(obj, { 
                some_key: {
                    param2 : "val2_new",
                    param3 : "val3_new"
                }
            })

            obj.save((err, obj) => {
                if(err) return reject(err)
                resolve(obj)
            })
        })
    })
}


function updateObject(obj, data) {

    let keys = Object.keys(data)

    keys.forEach(key => {

        if(!obj[key]) obj[key] = data[key]

        if(typeof data[key] == 'object') 
            obj[key] = updateObject(obj[key], data[key])
        else
            obj[key] = data[key]
    })

    return obj
}

使用$set执行此过程

.update({"_id": args.dashboardId, "viewData._id": widgetId}, {$set: {"viewData.$.widgetData": widgetDoc.widgetData}})
.exec()
.then(dashboardDoc => {
    return {
        result: dashboardDoc
    };
}); 

从Mongo 4.2开始，db.collection.updateMany()(或db.collection.update())可以接受一个聚合管道，它允许使用聚合操作符，如$addFields，它输出输入文档中所有现有的字段和新添加的字段:

var new_info = { param2: "val2_new", param3: "val3_new" }

// { some_key: { param1: "val1", param2: "val2", param3: "val3" } }
// { some_key: { param1: "val1", param2: "val2"                 } }
db.collection.updateMany({}, [{ $addFields: { some_key: new_info } }])
// { some_key: { param1: "val1", param2: "val2_new", param3: "val3_new" } }
// { some_key: { param1: "val1", param2: "val2_new", param3: "val3_new" } }

The first part {} is the match query, filtering which documents to update (in this case all documents). The second part [{ $addFields: { some_key: new_info } }] is the update aggregation pipeline: Note the squared brackets signifying the use of an aggregation pipeline. Since this is an aggregation pipeline, we can use $addFields. $addFields performs exactly what you need: updating the object so that the new object will overlay / merge with the existing one: In this case, { param2: "val2_new", param3: "val3_new" } will be merged into the existing some_key by keeping param1 untouched and either add or replace both param2 and param3.

我用自己的函数解出来了。如果你想更新文档中的指定字段，你需要清楚地解决它。

例子:

{
    _id : ...,
    some_key: { 
        param1 : "val1",
        param2 : "val2",
        param3 : "val3"
    }
}

如果你只想更新param2，这样做是错误的:

db.collection.update(  { _id:...} , { $set: { some_key : new_info  } }  //WRONG

你必须使用:

db.collection.update(  { _id:...} , { $set: { some_key.param2 : new_info  } } 

所以我写了一个这样的函数:

function _update($id, $data, $options=array()){

    $temp = array();
    foreach($data as $key => $value)
    {
        $temp["some_key.".$key] = $value;
    } 

    $collection->update(
        array('_id' => $id),
        array('$set' => $temp)
    );

}

_update('1', array('param2' => 'some data'));