如何更新数组中的对象详细信息？

Question

我想更新我的 mongo 文档中的份量、卡路里和营养成分。我如何才能更新详细信息？

{
"_id": ObjectId("id"),
"user_id": ObjectId("id"),
"date": 20170210,
"snacks": [
  {
  "nutrients": {
    "protein": "0",
    "carbs": "0",
    "fat": "0"
  },
  "servings": 1,
  "calories": 0.35,
  "name": "Coca-Cola zero"
 }
],
"dinner": [ ],
"lunch": [ ],
"breakfast": [ ]
}

我试过使用 $set 但它根本没有用。这是我一直在尝试的：

     user_food.update({user_id : req.session.user_id, date: 20170210, snacks:{name:"Coca-Cola zero"}}, {'$set':{'servings': 2}}, function(err, other){
        if(err){
            console.log("something went wrong: " + err);
            return res.status(500).send(err);
        }
        else{
            console.log("this is other: " + other);
            return res.status(200).send(other);
        }
    });

已解决

有效的查询：

        user_food.update({user_id : req.session.user_id, date: 20170210, 'snacks.name': food},{$set: {'snacks.$.servings': serving}},function(err, other){
        if(err){
            console.log("something went wrong: " + err);
        return res.status(500).send(err);
        }
        else{
            console.log("this is other: " + other);
        return res.status(200).send(other);
        }
    });

Answer 1

您必须指定记录必须具有属性snacks.name = 'Coca-Cola zero' 而不是snacks = {name: 'Coca-Cola zero'}。

所以你的查询应该是这样的：

user_food.update({
  user_id : req.session.user_id,
  date: 20170210,
  'snacks.name': 'Coca-Cola zero'
},{
  $set: {'snacks.$servings': 2}
},
function(err, other){
  if(err){
    console.log("something went wrong: " + err);
    return res.status(500).send(err);
  }
  else{
    console.log("this is other: " + other);
    return res.status(200).send(other);
  }
});