Pull and addtoset at the same time with mongo

Question

I have a collection which elements can be simplified to this:

{tags : [1, 5, 8]}

where there would be at least one element in array and all of t

Answer 1

If you're removing and adding at the same time, you may be modeling a 'map', instead of a 'set'. If so, an object may be less work than an array.

Instead of data as an array:

{ _id: 'myobjectwithdata',
  data: [{ id: 'data1', important: 'stuff'},
         { id: 'data2', important: 'more'}]
}

Use data as an object:

{ _id: 'myobjectwithdata',
  data: { data1: { important: 'stuff'},
          data2: { important: 'more'} }
}

The one-command update is then:

db.coll.update(
  'myobjectwithdata', 
  { $set: { 'data.data1': { important: 'treasure' } }
);

Hard brain working for this answer done here and here.