如何在mongodb中合并两个collections，聚合mongodb

Question

我有 2 个 collections：配置和点 点集合有一个名称字段，用于存储配置集合的 id

假设集合有一个数组，其中包含要搜索的对象，如何组合两个排序规则。

配置：

{
    "find": true,
    "points": [{
        "image": true,
        "brand": true,
        "_id": {
            "$oid": "61f0ad909535d94c98056e11"
        },
        "name": "ABC"
    }, {
        "image": true,
        "brand": true,
        "_id": {
            "$oid": "61f0ade99535d94c98056e17"
        },
        "name": "Odido"
    }]
}

积分

{
    "name": "61f0ad909535d94c98056e11",
    "userID": "61c49f94a02ff82b484cc6d0",
    enter code here
    "create_date": {
        "$date": "2022-01-27T02:53:52.473Z"
    }
}

我想得到这个结果，好吧，或者类似的东西

{
    "name": "61f0ad909535d94c98056e11",
    "userID": "61c49f94a02ff82b484cc6d0",
    "config_name": {
        "image": true,
        "brand": true,
        "_id": {
            "$oid": "61f0ad909535d94c98056e11"
        },
        "name": "ABC"
    },
    "create_date": {
        "$date": "2022-01-27T02:53:52.473Z"
    }
}

我正在尝试使用这样的查询

    Points.aggregate([
          {
            $lookup: {
              from: "configs",
              localField: "name",
              foreignField: "_id",
              as: "configs",
            },
          },
        ]);

在此先感谢您的帮助：）

Answer 1

db.points.aggregate([
  {
    $match: { "name": "61f0ad909535d94c98056e11" }
  },
  {
    $set: { "name": { "$toObjectId": "$name" } }
  },
  {
    $lookup: {
      from: "configs",
      localField: "name",
      foreignField: "points._id",
      as: "config_name"
    }
  },
  {
    $set: {
      "config_name": {
        "$first": {
          "$filter": {
            "input": { "$first": "$config_name.points" },
            "as": "item",
            "cond": { "$eq": [ "$name", "$$item._id" ] }
          }
        }
      }
    }
  }
])

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