Question

In the document below, I have an array called imAccounts. I want to update() the object in that array. How can I do that?

{
"_id" : ObjectId("503c55da1c192a530b000001"), 
"imAccounts" : [
  { 
    "accountType"     : "Windows",  
    "accountName"     : "rwqerqw",  
    "accountPassword" : "erqwerwe" 
  }, 
  {     
    "accountType"     : "Yahoo",    
    "accountName"     : "rwqerqw",  
    "accountPassword" : "erqwerwe" 
  }]
}

Answer 1

With this document structure you can update an object in the array using the positional operator ($):

db.myarray.update(
    { // Match criteria
        "_id" : ObjectId("503c55da1c192a530b000001"),
        'imAccounts.accountType': 'Yahoo',
    },
    { // Update first matched item using positional operator $
        '$set' : { 'imAccounts.$.password':'sekrit'}
    }
)

Note that the positional operator currently only applies to the first matched item in the query.