mongoDB，带有 $sum 和 $count 的 mongoose 聚合查询

Posted 2023-03-10

【中文标题】mongoDB，带有 $sum 和 $count 的 mongoose 聚合查询

【英文标题】：mongoDB, mongoose aggregation query with $sum and $count

【发布时间】：2021-08-23 00:26:15

【问题描述】：

世界！ 我是 mongodb 的新手，我不知道我可以通过聚合和求和等来完成这项任务..( 所以，我有这个系列： 这是商店集合

"storeName": "store one",
"_id" : ObjectId("store id 1"), // this is store ID
"shopId" : ObjectId("shopId 1"),
"shopItems" : [
    
        "_id" : ObjectId("6048a1fa31d779032b16301e"),
        "itemId" : ObjectId("111"), // this is product id from PRODUCTS collection
        "itemCount" : 2
    ,
    
        "_id" : ObjectId("6048a46e31d779032b163043"),
        "itemId" : ObjectId("222"),// this is product id from PRODUCTS collection
        "itemCount" : 0
    
  ],
,

   "storeName": "store two"
   "_id" : ObjectId("storeId 2"), // this is store ID
   "shopId" : ObjectId("shopId 2"),
   "shopItems" : [
    
        "_id" : ObjectId("6048a1fa31d779032b16301e"),
        "itemId" : ObjectId("222"), // this is product id from PRODUCTS collection
        "itemCount" : 2
    ,
    
        "_id" : ObjectId("6048a46e31d779032b163043"),
        "itemId" : ObjectId("333"),// this is product id from PRODUCTS collection
        "itemCount" : -5
    
            
        "_id" : ObjectId("6048a46e31d779032b163043"),
        "itemId" : ObjectId("111"),// this is product id from PRODUCTS collection
        "itemCount" : -7
    
  ],

这是产品集合，这是一个不同价格的数组， 实际上还有更多〜50/50。我收集了 boolean 表示商店的价格 是不同的（也许对任务有帮助）

// products collection

    "_id" : ObjectId("111"), // itemId in STORE collection
    "differentPricesForShops" : false,
    "productName" : "some name here",
    "buyPrice" : 10,
    "sellingPrice" : 100,
    "differentPricesForShops" : false,
    "difPriceArray" : []
,

    "_id" : ObjectId("222"), // itemId in STORE collection
    "differentPricesForShops" : false,
    "productName" : "some name here",
    "differentPricesForShops" : true, <- TRUE
    "difPriceArray" : [
        
            "shopId": ObjectId("shopId1") <- shop
            "buyPrice" : 5,   <- differentPrices
            "sellingPrice" : 50,
        ,
        
            "shopId": ObjectId("shopId 2")
            "buyPrice" : 15,
            "sellingPrice" : 55,
        ,
    ]
,

    "_id" : ObjectId("333"), // itemId in STORE collection
    "differentPricesForShops" : false,
    "productName" : "some name here",
    "buyPrice" : 5,
    "sellingPrice" : 15,
    "differentPricesForShops" : false,
    "difPriceArray" : []
,

我需要这个输出数据：

"shopId" : ObjectId("6048a15031d779032b16300f"),

产品数量：2，

产品负数：0，

selfprice: (2-> 店内计数 * 10(buyPrice) ) = 20

待售产品：（2 -> 店内数量 * 100（售价））= 200

---

"shopId" : ObjectId("6048a15031d779032b16300f"),

产品数量：2，

减号产品：-5（店内商品数）+ -7（店内商品数）= -12

selfprice：（2-> 店内数 * 15（不同店价））= 30

待售产品：（2 -> 店内数量 * 55（各店价格不同））= 110

---

这个例子是按 1 个产品，但 我需要有 selfPrice 和待售产品的总和。 请检查图片 我需要这样显示数据：

data in table img

我希望有人可以帮助我。非常感谢！

【参考方案1】：

此聚合查询将为您提供所需的输出：

管道阶段：

unwind : 这将为给定商店的每个产品创建单独的文档

lookup : 这将用于连接和获取产品详细信息

unwind : 因为查找结果是数组，所以将它作为文档/对象

addfields：检查价格是否存在差异，然后设置适当的值

addfields：将上述步骤中匹配的商店 $buyPrice 和 $ sellPrice 从对象转换为字段

addfields：根据上述步骤中的 $buyPrice 和 $ sellPrice 设置 selfprice 和 products_for_sale

组：以我们想要的方式提取字段！

  [$unwind: 
       path: '$shopItems' 
     , $lookup: 
       from: 'products',
       localField: 'shopItems.itemId',
       foreignField: '_id',
       as: 'shop_products'
     , $unwind: 
       path: '$shop_products'

     , $addFields: 
       buyPrice:  $cond:  if: $anyElementTrue:["$shop_products.difPriceArray"], 
       then:
                  $arrayElemAt:[$filter: 
                    input: "$shop_products.difPriceArray",
                    as: "item",
                    cond:  $eq: [ "$$item.shopId", '$shopId' ] 
                 
              ,0]
           , 
       else: '$shop_products.buyPrice',
       sellingPrice:  $cond:  if: $anyElementTrue:["$shop_products.difPriceArray"], 
       then:
                  $arrayElemAt:[$filter: 
                    input: "$shop_products.difPriceArray",
                    as: "item",
                    cond:  $eq: [ "$$item.shopId", '$shopId' ] 
                 
              ,0], 


           else: '$shop_products.sellingPrice',
     , $addFields: 
       buyPrice:   $cond:  if: $eq: [$type: '$buyPrice',"object"] , then: '$buyPrice.buyPrice' ,else:'$buyPrice',
       sellingPrice:   $cond:  if: $eq: [$type: '$sellingPrice',"object"] , then: '$sellingPrice.sellingPrice' ,else:'$sellingPrice'
     , $addFields: 
     selfprice:  $multiply: [ $ifNull:['$shopItems.itemCount',0], $ifNull:[ '$buyPrice',0]] ,
     products_for_sale  : $multiply: [ $ifNull:['$shopItems.itemCount',0], $ifNull:[ '$sellingPrice',0]] ,

     , $group: 
       _id: '$_id',
       selfprice:$sum: 
                      $cond:  if:  $lt: [ "$selfprice", 0 ] , then: 0, else: '$selfprice'  
                    ,
       product_count:$sum:1,
       shopId:$first:'$shopId',
       product_in_minus:$sum: 
                      $cond:  if:  $lt: [ "$shopItems.itemCount", 0 ] , then: "$shopItems.itemCount", else: 0 
                     ,
       products_for_sale:$sum: 
                      $cond:  if:  $lt: [ "$products_for_sale", 0 ] , then: 0, else: '$products_for_sale'  
                     
     ]

Mongo 游乐场：https://mongoplayground.net/p/P7xYYEQBJ-J