Question

My database will not update my active_quests. All I am trying to do is replace one array of hashes with another, updated array of hashes. I assumed would be the simplest way of handling this. Here’s the code:

# construct the query
query = Player.where( :_id => player_id).fields( :xp, :lvl_prgrssns, :active_quests, :completed_quests )

# get the player
player = query.first

if !player.nil?
    return_val = player.set( :active_quests => [{"quest_id" => "123"}, {"quest_id" => "456"}])
    logger.debug "return_val = "+return_val.to_s # comes out as 180
end

My understanding is that, if the return from a set is positive, that means that the set was successful. It returns as 180 in this simplified case but the active_quests never get updated on the player. I can go into the mongo console and execute this:

db.players.update({_id:ObjectId("50756b1896f4f5121a00000a")}, {$set:{active_quests:[{"quest_id":"1"}, {"quest_id":"2"}] }});

and active_quests will update as expected but no matter what I try in rails the update appears to go through but nothing updates.

Here are some of the many alternatives I have tried (all have been tried with and without .to_mongo and with and without player.save after them):

Player.where( :_id => params[:player_id] ).update(:active_quests => active_quests_list.to_mongo)

player.update_attributes(:active_quests => active_quests_list.to_mongo)

player_update = player.as_json
player_update["active_quests"] = active_quests_list
player.update_attributes(player_update)

return_val = query.update( "$set" => {:active_quests => player.active_quests.to_mongo} )

return_val = query.update( {:_id => params[:player_id]}, {"$set" => {:active_quests => active_quests_list.to_mongo}})

I’m hoping someone here might know what I am doing wrong.

Answer 1

After further investigation, it turns out that this was a problem relating to how the player variable was being updated outside of the function.

The following lines will update the record in this case (both in-memory and in the database)

player[:active_quests] << @active_quests_list
player.push_all(:active_quests => player.active_quests)

However, the player variable was local to this function in this case, and was being updated again after the function returned.

This was only discovered after careful examination of the output of “mongod -vvvvv”.