mongodb - How to query a collection that matches the exact fields of objects in array -

how query collection matches exact fields of objects in array?

since test case more explicit, here test pass.

a = invitation.create(guests: [ guest.new(player: 'bbb'), guest.new(player: 'ccc') ]) b = invitation.create(guests: [ guest.new(player: 'ccc'), guest.new(player: 'bbb') ]) c = invitation.create(guests: [ guest.new(player: 'bbb'), guest.new(player: 'ccc'), guest.new(player: 'ddd') ])  # request find invitation bbb , ccc player_id of guests, regardless order. result = invitation.collection.find(...) assert_equal result, [ a, b ] 

my use case invitation system same combination of guests can't exist, when new invitation sent, need check if 1 exact same guests (regardless order).

note: use array of guest objects since carry additional data. here example data set (https://gist.github.com/anonymous/5507735).

based on answer nyde1319; feels hackish, since there's no other answers yet here goes:

db.invitation.find({'guests.player':{'$all':['bbb','ccc']}, guests: {$size: 2}}) 

the number 2 in {$size: 2} of course depends on length of array.