Mongo查询(带有位置运算符)不适用于猫鼬 [英] Mongo query (with positional operator) does not work in mongoose

问题描述

给出一个包含果园的数据库集合，一个对象看起来像这样:

Given a database collection with orchards, one object looks like this:

{
"orchardId" : ObjectId("5391c137722b051908000000"),
"trees" : [ 
    {
        "name" : "apple",
        "fruits" : []
    }, 
    {
        "name" : "pear",
        "fruits" : [ 
            ObjectId("54c54291d93236150f00004e"), 
            ObjectId("54c542c9d93236150f000062")
        ]
    }
]
}

我想动态地将水果添加到特定的树上.我知道我可以在mongo中执行以下操作:

I want to dynamically add a fruit to a specific tree. I know I can do this in mongo with:

db.orchards.update(
    ({"orchardId": ObjectId("5391c137722b051908000000")},
    {"trees" : { $elemMatch: {"name":"apple"}}}),
    { $push: { "trees.$.fruits": ObjectId("54c542c9d900000000001234") }}
)

所以，如果我是对的，那应该是猫鼬了.

So, if I'm right this should be this in mongoose:

orchards.update(
    ({"orchardId": ObjectId.fromString(orchard.id)},
    {"trees" : {$elemMatch: {"name": "apple"}}}),
    {$push: {"trees.$.fruits": ObjectId("54c542c9d900000000001234") }},function(err, data){ ...

但是随后我收到一条错误消息:[TypeError:无法调用未定义的方法'path']

But then I get an error saying: [TypeError: Cannot call method 'path' of undefined]

猫鼬似乎无法处理位置运算符($)，因为当我将$更改为0时，它确实起作用.

It looks like mongoose can't handle the positional operator (the $) because when I change the $ with a 0 it does work.

我如何用猫鼬做这项工作?

How do I make this work in mongoose?

推荐答案

在您的代码示例中，您有括号中应有括号的地方，因此应改为:

In your code sample you've got parens where you should have braces, so it should be like this instead:

orchards.update({
    "orchardId": ObjectId(orchard.id),
    "trees": {$elemMatch: {"name": "apple"}}
  },
  {$push: {"trees.$.fruits": ObjectId("54c542c9d900000000001234") }},
  function(err, data){ ...

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