Can't update document in mongodb (want to push item in array)

Question

at first i apologize for my english :(
im new at nodeJs and mongodb and i have a problem
I can't add any item into array
This is what i tried:

db.conversations.update({userID: memberID} ,{
       "user_users" : {
           $push : { "member": userID } // this does not work :((
          }
         });

and i also tried this:

db.conversations.user_users = {
            $push : {
                 member: memberID
             }
            };
            db.conversations.save();

i want to work like this :

{
"_id" : conversationID,
"userID" : userID,
"user_users" : { "member" : memberID,  "member" : memberID }
}

possible duplication -> http://stackoverflow.com/questions/33049707/push-items-into-mongo-array-via-mongoose?rq=1 — admix, Jan 07 '16 at 22:29
`$push` only works for arrays. `user_users` in the document above is an object. — Brian Shamblen, Jan 07 '16 at 22:29
@brian-shamblen yes you are right but now how can i do this? — Hamet Gholizadeh, Jan 07 '16 at 22:55

score 4 · Accepted Answer · answered Jan 07 '16 at 22:58

The following JSON :

{
    "_id": conversationID,
    "userID": userID,
    "user_users": {
        "member": memberID,
        "member": memberID
    }
}

is not valid, because "member" is a duplicated key. What you could do is to transform user_users to an array of users and do something like this :

{
    "_id": conversationID,
    "userID": userID,
    "user_users": [
        {
            "member": memberID
        },
        {
            "member": memberID
        }
    ]
}

where each member of the array user_users is a document. You would then be able to do the following query to add members to your array :

db.conversations.update(
    {userID: memberID} ,
    {$push : {"user_users" : { "member": userID }}}
)

really helps me ♥ tnx – Hamet Gholizadeh Jan 08 '16 at 21:08 — Hamet Gholizadeh, Jan 08 '16 at 21:08

Can't update document in mongodb (want to push item in array)

1 Answers1