Mongo find documents where array contains x values of given array

Question

I have a collection which has documents like that one. The entity field is not set in each document and has different values:

{
    \"_id\" : ObjectId(\"5388         


        

Answer 1

You can use .aggregate for this. This is probably what you're looking for:

var y = ["Entity1", "Entity2", "Entity3", "Entity4"];
db.col.aggregate([
    {
        $project :
        {
            _id : 1,
            name : 1,
            entity : 1,
            x : {
                $size : {
                    $ifNull: [{$setIntersection : ["$entity", y]}, []]
                }
            }
        } 
    },
    { $match : { x : 3 } }
]);