猫鼬-基于枚举值的聚合$ match [英] Mongoose - Aggregation $match based on enum values

问题描述

我与猫鼬聚合，我得到的对象看起来像这样:

I have an aggregation with mongoose, the objects what i get looks like this:

foods: {
  fruits: {
    apple: 'NONE',
    banana: null,
    pearl: 'INCLUDED'
  }
}

水果可以有4个值:null，'NONE'，'INCLUDED'，'EXTRA'

The fruits can have 4 values: null, 'NONE', 'INCLUDED', 'EXTRA'

我的目标是在此聚合中创建$ match/filter，以便能够过滤出null和'NONE'值.

My goal is to make the $match/filter in this aggregation, to be able to filter out the null and 'NONE' values.

是否可以选择执行此操作?

Is there any option to do this?

就像聚合一样，我有这个:

Like at the aggregation i have this:

    {
        $match: 'foods.fruits.pearl',
    }

然后取回那些珍珠具有'INCLUDED'或'EXTRA'值的物体吗?

Then get back those objects where the pearl have 'INCLUDED' or 'EXTRA' value?

推荐答案

您可以在mongodb 3.4.4 及更高版本

You can try below aggregation in mongodb 3.4.4 and above

好吧，您这里的未知键具有NONE和null的值，因此，您可以使用

Well you have unknown keys here having value with NONE and null and therefore, you can use $objectToArray aggregation to make keys into values and can easily $match with them

db.collection.aggregate([
  { "$addFields": {
    "data": { "$objectToArray": "$foods.fruits" }
  }},
  { "$match": { "data.v": { "$in": [ "NONE", null ] } } },
  { "$project": { "data": 0 }}
])

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