mongoose：在数组内应用 object 值的 $addToSet？

Question

game_data: [{
   id: 'HUH',
   name: 'GTA'
   story: 'ahhhh'
}]

I have a field like above. I want to check incoming data to avoid duplicate on the value id .

incomingg_dataA: {
       id: 'HUH',
       name: 'Dota2'
       story: 'hmmm'
    }

Like this case, if the incomingg_dataA contains the same id HUH . I want to use that value to $addToSet . If the id is different

incomingg_dataB: {
       id: 'HUUUH',
       name: 'Dota2'
       story: 'hmmm'
    }

then, it would be

game_data: [{
   id: 'HUH',
   name: 'GTA'
   story: 'ahhhh'
}, 
{
   id: 'HUUUH',
   name: 'Dota2'
   story: 'hmmm'
}];

I could do the entire document as $addToSet but then, I am kinda afraid that someone will just change the story part and it will still be registered.

Is there any way that I can do this with $addToSet or do I just have to do the.find() and callback function?

Answer 1

You have to add the $ne condition in your find query with the id value you want to avoid duplicate.

db.col.update({
  // All the find conditions you want
  // Plus the below condition
  "game_data.id": {"$ne": incomingg_dataB['id']},  // Updated only when the `id` is not already present in the array
}, {
  "$push": {
    "game_data": incomingg_dataB,
  }
})