mongodb find exact document -

im looking way in mongodb find exact document, meaning dont want match document other fields ones expected.

this can on subdocuments

> db.test.insert({a:{b:1,c:2}}); > db.test.insert({a:{b:1}}); > db.test.find({'a.b':1}); // non exact match {a:{b:1,c:2}} {a:{b:1}} > db.test.find({'a':{'b':1}}); // exact match {a:{b:1}} 

i'd same on main document (not subdocument). but

> db.test.insert({b:1,c:2}); > db.test.insert({b:1}); > db.test.find({'b':1}); // non exact match {a:{b:1,c:2}} {a:{b:1}} > db.test.find({'.':{'b':1}}); // not work :( > db.test.find({'b':1, 'c':null}); // works, how supposed know 'c' exists ??? {a:{b:1}} 

the final goal being $pull on arrays

> db.test.insert({a:[{b:1,c:2},{b:1,d:3},{b:1,c:2},{b:1,c:2,d:3}]}); > db.test.update({}, {$pull:{'a':{b:1,c:2}}}); > db.test.find(); {a:[{b:1,d:3}]} // noooo :'( 

has idea ?

edit :

here precision on exact / partial matching found on arrays :

• array item exact matching : db.test.find({'a':{b:1,c:2}});
• array item partial matching : db.test.find({'a':{$elemmatch:{b:1,c:2}}});
• array item removal partial matching : db.test.update({}, {$pull:{'a':{b:1,c:2}}})
• array item removal exact matching : db.test.update({}, {$pullall:{'a':[{b:1,c:2}]}}) (thanks johnnyhk)

it's not documented, if use $pullall instead of $pull, matching elements removed:

db.test.update({}, {$pullall:{a: [{b:1,c:2}]}});