mongoDB mongoose 按月和总和分组

Question

我有这个orderdetails模型

const model = new Schema(
  {
    district: { type: String },
    category: String,
    producer: String,
    variety: String,
    qty: String,
    price: String,
    subtotal: String,
  },
  { timestamps: true }
);

我想在 variety 之前得到月度销售报告。首先，我过滤 variety 然后按月分组，然后计算 qty

的总和

这是我的查询

 const monthly = await OrderDetails.aggregate([
      {
        $match: {
          variety,
        },
      },
      {
        $group: {
          _id: {
            
            month: { $month: "$createdAt" },
            qty: { $sum: { $toInt: "$qty" } },
          },
        },
      },

      { $sort: { _id: 1 } },
      {
        $project: {
          qty: "$_id.qty",
          Month: {
            $arrayElemAt: [
              [
                "",
                "Jan",
                "Feb",
                "Mar",
                "Apr",
                "May",
                "Jun",
                "Jul",
                "Aug",
                "Sep",
                "Oct",
                "Nov",
                "Dec",
              ],
              "$_id.month",
            ],
          },
        },
      },
    ]);

但是输出是这样的

这个查询的输出是这个

[
  { _id: { month: 4, qty: 1 }, qty: 1, Month: 'Apr' },
  { _id: { month: 4, qty: 5 }, qty: 5, Month: 'Apr' }
]

但是预期输出是一条记录，总数量是6条这样

[
  { _id: { month: 4, qty: 6 }, qty: 6, Month: 'Apr' },
 
]

我的查询有什么问题？

Answer 1

由于 qty 用于累加器，因此将您的 $group 从

更改为

  {
    $group: {
      _id: {
        month: { $month: "$createdAt" },
        qty: { $sum: { $toInt: "$qty" } }
      }
    }
  }

到

  {
    $group: {
      _id: { month: { $month: "$createdAt" } },
      qty: { $sum: { $toInt: "$qty" } }
    }
  }

mongoplayground

mongoDB mongoose 按月和总和分组

mongoDB mongoose group by month and total sum

javascript

node.js

mongodb

mongoose