按 id 分组并按 mongoose express 节点 js 中的总计数获取订单
我有一个这样的集合：
{
"_id": {
"$oid": "5f54b3333367b91bd09f4485"
},
"products": [
{
"_id": 20,
"name": "Türk Kahvesi",
"price": 8,
"count": 2
},
{
"_id": 22,
"name": "Dibek",
"price": 10,
"count": 2
},
{
"_id": 21,
"name": "Damla Sakızlı T.K.",
"price": 10,
"count": 1
}
],
"deskId": "5f53473611f7490d3c860ccd",
"waiterId": "1",
"deskName": "Ü2",
},
{
"_id": {
"$oid": "5f54af663367b91bd09f4483"
},
"products": [
{
"_id": 20,
"name": "Türk Kahvesi",
"price": 8,
"count": 1
},
{
"_id": 21,
"name": "Damla Sakızlı T.K.",
"price": 10,
"count": 1
},
{
"_id": 22,
"name": "Dibek",
"price": 10,
"count": 1
},
{
"_id": 23,
"name": "Menengiç",
"price": 10,
"count": 1
},
{
"_id": 25,
"name": "Double Espresso",
"price": 15,
"count": 6
}
],
"deskId": "5f53473611f7490d3c860ccd",
"waiterId": "1",
"deskName": "Ü2",
}
我的目标是，获取所有数据顺序并按 product._id 分组并显示 totalPrice(price*count)、products.name、_id 和 totalCount。这实际上是一个产品一个产品地给我们展示一个报告。如果您需要更多信息，请询问。示例结果：
{
{
"_id": 20,
"name": "Türk Kahvesi",
"totalCount": 3,
"totalPrice": 24
},
{
"_id": 22,
"name": "Dibek",
"totalCount": 3,
"totalPrice": 30
},
{
"_id": 21,
"name": "Damla Sakızlı T.K.",
"totalCount": 2,
"totalPrice": 20
},
{
"_id": 23,
"name": "Menengiç",
"totalCount": 1,
"totalPrice": 10
},
{
"_id": 25,
"name": "Double Espresso",
"totalCount": 6,
"totalPrice": 90
}
}
我们可以在某些东西上使用聚合。请帮我。
12345678_00011回答
-
慕婉清6462132
我对 MongoDB 还是个新手，但我认为这个聚合管道正是您要找的。也就是说，这是您应该使用文档自己研究的事情，但只要您了解思维过程，您就会学到一些东西，所以一切都很好！[ { $unwind: { path: '$products', // Here we are seperating each item in the products array of // the user(I presumed your objects were users, or carts maybe) // It will now be available to the next stage of the pipeline as // a singular object for each item in the array, // see the picture below for how this works practically. } }, { $group: { // Now we're going to restructure the object to // center around the id field of the products, and // at the same time we can add up the total price // and count of each item. _id: '$products.id', // This is the selector for the grouping process (in our case it's the id) item: { $first: '$$ROOT.products' }, // this is me thinking you'll want access to the item in question for each total. totalCount: { $sum: "$products.count" }, // adds to totalCount EACH $products.count that we have totalPrice: { $sum: { $multiply: ["$products.price", '$products.count'] } }, // self explanatory } }]这就是 unwind 对你的数组和对象所做的注意，出于实际原因，我修改/删除了一些变量名（_id、oid），您必须解析哪些变量名，如果复制粘贴，此代码很可能无法立即运行。
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相关分类
JavaScript