mongoid update elements within array

问题

I am using mongoid 3.1 with Ruby 1.9.3 and I am trying to update a value within an array. I can successfully perform the following command in mongodb's CLI, but can't seem to find the appropriate solution/translation for mongoid.

user.update( { activities: { $elemMatch: { uuid: "1111111-xxxx-xxxx" }}}, { $set: { 'activities.$.submitted': true }})

For context the document looks like:

{
   "_id" : ....,
   "user_name" : "bob",
   "activities: [ 
       {
          uuid: "1111111-xxxx-xxxx",
          submitted: true,
       },
       {
          uuid: "222222-xxxx-xxxx",
          submitted: false,
       },
       {
          uuid: "333333-xxxx-xxxx",
          submitted: false,
       }
   ]
}

The goal is to change submitted to true based on the uuid value. From what I can tell, all of the "updating" solutions in mongoid only deal with the attributes at the root of the document and can't have options for the $ positional operator.

Any help would be appreciated.

Thank you

回答1:

Looks like I found the answer in a github issue discussion.

The solution for me was:

User.elem_match(activities: { type: "redemption" }).elem_match(activities: { uuid: uuid }).update("$set" => {"activities.$.submitted" => true })

来源：https://stackoverflow.com/questions/18346287/mongoid-update-elements-within-array