从猫鼬等效的数组mongodb中删除一项 [英] Remove an item from an array mongodb equivalent in mongoose

问题描述

文档:

{
    "_id" : ObjectId("5399ba7f8035beb2d4717cc0"),
    "listName" : "firstList",
    "items" : [
        {
            "pName" : "iPad ",
            "pDesc" : "iPad aiiir",
            "ownerID" : ObjectId("5399b596c501732dd4d13923"),
            "_id" : ObjectId("5399e2cc2d7b0349d89d2b44"),
            "dateAdded" : ISODate("2014-06-12T17:26:36.282Z")
        },
        {
            "pName" : "iPhone ",
            "pDesc" : "5s",
            "ownerID" : ObjectId("5399b596c501732dd4d13923"),
            "_id" : ObjectId("5399e2cc2d7b0349d89d2b44"),
            "dateAdded" : ISODate("2014-06-12T17:26:36.282Z")
        }
]}

我想从数组"项中删除一项，不知道文档的_id仅该元素的ID， 我有这个查询，可以找到元素，它在mongodb shell中有效，但在mongoose中无效，

I want to remove an item from the "array" items without knowing the _id of the document only the id of the element, I have this query that finds the element, it works in mongodb shell but doesn't in mongoose,

db.lists.find( {items:
               {$elemMatch:{'_id':ObjectId("5399b596c501732dd4d13923")}}} , 
               {"items.$":1});

您知道为什么吗?

你能给我等价的猫鼬吗?

Can you please give me the equivalent in mongoose ?

我应该如何从仅知道其_id的列表中拉出项目?

How should I pull the item from the list knowing only its _id ?

推荐答案

这应该可以解决问题:

db.lists.update(
    {}, 
    { $pull: {"items": {"_id" :ObjectId("5399e2cc2d7b0349d89d2b44") }},
    { multi: true }})

对于集合中的每个文档({}表示空查询)，它将删除具有提供的_id(在items数组中)的每个项目.如果没有multi选项，则只会影响找到的第一个文档

For every document in the collection ({} means empty query), it removes every item with the provided _id (in the items array). Without the multi option, only the first document found will be affected

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