猫鼬不动findAndUpdateById [英] Mongoose unshift findAndUpdateById

问题描述

什么是通过findByIdAndUpdate将值 unshift 通过Mongoose文档数组的正确方法?

What's, if there is, the correct way to unshift a value into a Mongoose document's array through findByIdAndUpdate?

我尝试了此操作，但没有给出错误，但似乎也没有更新值

I tried this which doesn't give error but also doesn't seem to update the value

Schema.findById(id, function(err, doc){
    console.log(doc.array.length); // => 1
    Schema.findByIdAndUpdate(id, 
        { array: { unshift: { property: 'value' } } }, 
        { upsert: true },
        function(err, doc) { 
            console.log(doc.array.length); // Also => 1
        }
    );
});

$push有效. $unshift给出错误

[MongoError: exception: Unknown modifier: $unshift

文档说使用unshift代替，但它不起作用.还是我使用错了?它不会给出任何错误，只是不会更新数组.

Docs say to use unshift instead, but it doesn't work. Or am I using it wrong? It doesn't give any error, just doesn't update the array..

推荐答案

Found out that the $position operator in conjunction with $each works with $push to achieve the same.

{ array: { $push: { property: {$each: ['value'], $position: 0 } } } }, 

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