I have a collection in MongoDB that represents the chores kids needs to do each day and whether they are done. Here is an example of a document.

{
  "_id":"2022-02-13:joe",
  "kidName":"Joe",
  "chores": [
    {"chore":"Breakfast: clear dishes and utensils","done":true}, 
    {"chore":"Clearing dishes after meals","done":true},
    {"chore":"Put away coats, knapsack, and shoes","done":true}, 
    {"chore":"Clear toys","done":true}
   ],
    "date": 2022-02-13T00:00:00.000 00:00
  }

I want to change it so that, instead of a Boolean, done is an integer, where:

Is there a pipeline or trick in Compass to do this for all documents in the collection?

CodePudding user response：

You could use the update method with aggregation pipeline to update the chores array. You would need to use the following pipeline to achieve the desired results:

db.collection.updateMany(
    { 'chores.0': { '$exists': true } },
    [
        { '$set': {
            'chores': {
                '$map': {
                    'input': '$chores',
                    'as': 'chore',
                    'in': {
                        '$mergeObjects': [
                            '$$chore',
                            { 
                                'done': {
                                    '$switch': {
                                        'branches': [
                                            { 'case': { $eq: [ '$$chore.done', true ] }, then: 1 },
                                            { 'case': { 
                                                $eq: [ 
                                                    { $ifNull: ['$$chore.done', 'Unmarked'] }, 
                                                    'Unmarked' 
                                                ] }, 
                                                then: 0 
                                            },
                                            { 'case': { $eq: [ '$$chore.done', false ] }, then: -1 },
                                        ],
                                        default: 0
                                    }
                                }
                            }
                        ]
                    }
                }
            } 
        } }
    ]
)