Question

我想问的人。

所以我有3个收藏集：

brand：（brandId，brandName等...）
合作伙伴：（partnerId，partnerName等...）
合作伙伴关系：（partnersipId，brandId，partnerId等）

如您所见，我想通过partnerId将伙伴集合与伙伴集合一起加入，并且我已经加入了。但是我需要brandName成为伙伴关系集合上的brandName字段。我已经尝试过此查询：

db.getCollection('partner').aggregate([
    {
        $match: { partnerId: 107 }
    },
    {"$lookup":
        {
            "from" : "partnership",
            "localField" : "partnerId",
            "foreignField" : "partnerId",
            "as" : "partnership"
        }
    },
    {"$lookup" :
        {
            "from" : "brand",
            "localField" : "partnership.brandId",
            "foreignField" : "partnership.brandId",
            "as" : "partnership.brand"
        }
    }])

但没有运气：（

预期结果：

{
    partnerId: 107,
    partnerName: 'TEST',
    partnership: [
        {
            partnerId: 107,
            partnershipId: 'd8b674ab-3c3d-4772-b5e8-81b4c0279424',
            brandId: 66
            brandName: 'BrandNameId66'
        },
        {
            partnerId: 107,
            partnershipId: '13246d75-59ed-47c2-82c5-54f73ad25cf0',
            brandId: 77
            brandName: 'BrandNameId77'
        }
    ]
}

当前结果：

{
    partnerId: 107,
    partnerName: 'TEST',
    partnership: {
        brand: [
            {
                brandId: 1,
                brandName: 'BrandNameId1'
            },
            ...
        ]
    }
}

请帮助我。谢谢！

Answer 1

您需要先解除伙伴关系，然后再进行以下查找：

db.getCollection('partner').aggregate([
    {
        $match: { partnerId: 107 }
    },
    {"$lookup":
        {
            "from" : "partnership",
            "localField" : "partnerId",
            "foreignField" : "partnerId",
            "as" : "partnership"
        }
    },
    {$unwind:{path: "$partnership", preserveNullAndEmptyArrays: true}}
    {"$lookup" :
        {
            "from" : "brand",
            "localField" : "partnership.brandId",
            "foreignField" : "partnership.brandId",
            "as" : "partnership.brand"
        }
    }
    {$group:{
      _id:"$_id",
      partnerId:{$min:"$partnerId"},
      partnerName:{$min:"$partnerName"},
      partnership:{$push:"$partnership"}
    }}
])

链式查找聚合mongoDB多个集合

1 个答案: