插入C#MongoDB中的嵌套数组 [英] Insert into nested array in C# MongoDB

问题描述

在MongoDB中名为Users的集合中有以下document.我试图将<SpecificBeer>插入mycellar cellar的beersInCellar[]中.我已经尝试了filter和update对象中的各种组合，但是无法将头放在插入嵌套数组中.我知道如何find一个document并将东西插入其中，而不是不插入该文档的数组中.

I have the following document in a collection called Users in MongoDB. I am trying to insert a <SpecificBeer> into beersInCellar[] of the mycellar cellar. I've tried all kinds of combinations in the filter and update objects but just can't wrap my head around inserting into a nested array. I know how to find a document and insert things into it, just not into an array in that document.

{
    "_id" : ObjectId("5920751b6d4f6a27cf7985a8"),
    "name" : "FullName",
    "emailAddress" : "[e-mail]",
    "cellars" : [
        {
            "cellarId" : "mycellar",
            "cellarName" : "My Cellar",
            "beersInCellar" : [ ]
        }
    ]
}

SpecificBeer模型:

SpecificBeer model:

public class SpecificBeer
        {
            public string ourid 
            { 
                get
                {
                    return ID.ToString();
                } 
                set
                { 
                    ID = ObjectId.Parse(value); 
                }
            }
            [BsonId]
            private ObjectId ID {get; set;}
            public string year { get; set; }
            public string variant { get; set; }
            public string quantity { get; set; }
            public string numberForTrade { get; set; }
        }

插入方法

public async Task<SpecificBeer> AddBeerToList(string id, SpecificBeer specificBeer, string cellarId)
{
        var filter = Builders<User>.Filter.Eq(e => e.userId, id) & Builders<User>.Filter.Eq(e => e.cellars, cellarId);

        var update = Builders<Cellar>.Update.Push<SpecificBeer>(e => e.beersInCellar, specificBeer);

        await _collection.FindOneAndUpdateAsync(filter, update);
        return specificBeer;
}

推荐答案

您必须使用您必须包括cellars中的字段(cellarId)，以便mongoDB定位元素的索引，并将占位符($)替换为更新部分中从查询部分找到的索引，以进行推送beersInCellar中的元素.

You've to include the field(cellarId) from the cellars for mongoDB to locate the index of element and replace the placeholder($) with the found index from query part in the update part to push the element in beersInCellar.

类似

 var filter = Builders<User>.Filter.Eq(e => e.name, "FullName") & Builders<User>.Filter.ElemMatch(e => e.cellars, Builders<Cellar>.Filter.Eq(e => e.cellarId, "mycellar"));
 var update = Builders<User>.Update.Push(e => e.cellars[-1].beersInCellar, specificBeer);

Shell查询以供参考:

Shell Query for reference:

db.collection.update({"name" : "FullName", "cellars":{$elemMatch:{"cellarId":"mycellar"}}},{$push:{"cellars.$.beersInCellar":{"quantity":1, "year":1986}}})

MongoDB不具有对数组内部嵌套数组中的字段(例如quantity)进行更新的一流支持.

MongoDB doesn't have first class support for updating fields ( for example quantity ) in the nesting arrays inside arrays.

您可以跟踪将允许进行多级更新的吉拉.

You can track the jira which is going to allow multiple level updates.

https://jira.mongodb.org/browse/SERVER-27089

您现在可能想要重新访问您的结构.尝试将beersInCellar数组提升为顶级.

You may want to revisit your structure for now. Try promoting the beersInCellar arrays to top level.

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