MongoDB Positional Operator $ -

i got following document

{     _id : 91,     "myarray" : [          {             "a" : "1",             "b" : true         },          {             "a" : "1",             "b" : true         },          {             "a" : "1",             "b" : true         }     ] } 

and want update each myarray.b element false b true. running following query:

db.mydb.update({"arr.b" : true},{$set : {"arr.$.b":false}},false, true) 

and getting first array element updated not subdocuments.

{         _id : "91",         "myarray" : [              {                 "a" : "1",                 "b" : false             },              {                 "a" : "1",                 "b" : true             },              {                 "a" : "1",                 "b" : true             }         ]     } 

all sub-documents match arr.b:true criteria should updated arr.b = false. according video mongodb university situation possible.

i don't want use javascript function.

what missing? thanks

unfortunately updating documents in array not possible - see mongodb jira ticket use positional operator update items in array.

you can update each document manually:

db.mydb.find({}).foreach(function(doc) {    doc.myarray.foreach(function(item) {       if (item.b === true)          item.b = false;    });     db.mydb.update({ "_id": doc._id }, { "$set": { "myarray": doc.myarray }}); });