mongodb update objects inside arrays of large collection

Question

say I wanted to update thousands of mongodb models with one click, would I run into unexpected problems? The idea is to update all entries as soon as there is a third language added to the webapp.

Model:

JobSchema = new mongoose.Schema({
    info:{ 
        instruments:[{
            index:String,
            de:String,
            en:String,
        }],
    },
});

Custom Updating (thousands of results):

Job.find({}, function(err, foundJobs){
     //no error handling for the sake of simplicity
     foundJobs.forEach(function(job){
         job.info.instruments.forEach(function(instr, index){
             instr.en = 'FOO'
         })    
     })
})

I know the better idea would be to create an extra "Instrument" model, but then I couldn't search for JobModels containing certain instruments...at least I couldn't find a good method...

Answer 1

Try this...

Job.updateMany({}, 
    { $set: { instruments.$.en: 'FOO' }, (err, result) => {
     if (err) {
         next(err);
     } else {
         res.status(200).json(result);
     }
});

I know the better idea would be to create an extra "Instrument" model, but then I couldn't search for JobModels containing certain instruments...at least I couldn't find a good method...

you could search by Id's of a references array in Job.

JobSchema = new mongoose.Schema({
    info:{ 
        instruments: [{type: mongoose.Schema.Types.ObjectId, ref: 'Instrument'}],
    }
});

InstrumentSchema = new mongoose.Schema({
        index:String,
        de:String,
        en:String
});

// assuming instrumentIDs is an array containing instrument object IDs.
JobSchema.find({ info.instruments: {$all : instrumentIDs } })

imho, if the update you're describing happens once in a full moon, it's not worth normalizing over it.