mongodb - How to not list all fields one by one in project when aggregating? -


i using mongo 3.2.14

i have mongo collection looks this:

{ '_id':... 'field1':... 'field2':... 'field3':... etc... }

i want aggregate way:

db.collection.aggregate{                         '$match':{},                         '$project':{                                     'field1':1,                                     'field2':1,                                     'field3':1,                                     etc...(all fields)                                     }                         }

is there way include fields in project without listing each field 1 one ? (i have around 30 fields, , growing...)

i have found info on here:

mongodb $project: retain previous pipeline fields

include existing fields , add new fields document

how not write every field 1 one in project

however, i'm using mongo 3.2.14 , don't need create new field, so, think cannot use $addfields. but, if could, can show me how use it?

basically, if want attributes of documents passed next pipeline can skip $project pipeline. if want attributes expect "_id" value can pass

{ $project: { _id: 0 } }

which return every value except _id.

and if chance have embedded lists or nests want flatten, can use $unwind pipeline


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