mongo 查找聚合覆盖整个对象

Question

我正在尝试填充声明对象内的 actions 数组中存在的 added_by 字段 这是一个例子：

{
    _id: ObjectId('.....'),
        actions: [
            {

                added_by: ObjectId('64d4f8a3fd3df..'),
                message: 'test'
            },
            {

                added_by: ObjectId('64d4f8a3fd3....'),
                message: 'test2'
            },
            //rest of records
        ]
}

我想要实现的是：

{
    _id: ObjectId('.....'),
        actions: [
            {
                added_by: {

                    "email": "[email protected]",
                    // rest of properties
                }
                message: 'test'
            },
            {

                added_by: added_by: {
                "email": "[email protected]",
                // rest of properties
            },
                message: 'test2'
                },
                 //rest of records
]
        }

我尝试这样做：

lookup.push({
      $lookup: {
        from: 'users', // The collection you are performing the lookup on (users collection)
        let: { actions: '$actions' }, // Variable for matching IDs
        as: 'actions', // The field to store the populated results
        pipeline: [
          {
            $match: {
              $expr: {
                $in: ['$_id', '$$actions.added_by'], // Match users whose '_id' is in the 'added_by' array
              },
            },
          },
        
         
        ],
      },
    });

但它有很多问题 1 - 它会覆盖整个对象，因此它将是这样的（消息字段将被删除 2-例如，如果 2 个操作是由同一用户在输出上创建的，我只找到 1 个用户，而不是输出同一用户两次

知道如何解决吗？

{
        _id: ObjectId('.....'),
            actions: [
                {
                    added_by: {
    
                        "email": "[email protected]",
                        // rest of properties
                    }
                    
                },
                {
    
                    added_by: added_by: {
                    "email": "[email protected]",
                    // rest of properties
                },
                  
                    },
                     //rest of records
    ]
            }

这是一个完整的例子 索赔文件：

{
    _id: ObjectId('64d79a9b5239b08bb7c00bb0'),
    claim_message: 'hola',
    files: [],
    added_by: ObjectId('64d4f8a3fd3dfa4fd2a37607'),
    company: ObjectId('64d4b30dfd3dfa4fd2a37283'),
    services: [
        ObjectId('64d4b0f4fd3dfa4fd2a3720f')
    ],
    status: 'open',
    createdAt: ISODate('2023-08-12T14:43:39.343Z'),
    updatedAt: ISODate('2023-08-12T18:57:40.162Z'),
    actions: [
        {
            files: null,
            added_by: ObjectId('64d4f8a3fd3dfa4fd2a37607'),
            message: 'testing'
        },
        {
            files: null,
            added_by: ObjectId('64d4f8a3fd3dfa4fd2a37607'),
            message: 'new reply'
        },
        {
            files: null,
            added_by: ObjectId('64d4f8a3fd3dfa4fd2a37879'),
            message: 'another reply'
        },


    ]
}

用户收藏

{
    {
        _id: ObjectId('64d4f8a3fd3dfa4fd2a37607'),
        account_type: 'CLIENT',
        email: '[email protected]',
        
    },
    {
        _id: ObjectId('64d4f8a3fd3dfa4fd2a37879'),
        account_type: 'CLIENT',
        email: '[email protected]',
        
    }
}

Answer 1

一个选项是：

db.claims.aggregate([
  {
    $lookup: {
      from: "users",
      let: {
        actions: "$actions"
      },
      as: "actionUsers",
      pipeline: [
        {
          $match: {
            $expr: {
              $in: [
                "$_id",
                "$$actions.added_by"
              ]
            }
          }
        }
      ]
    }
  },
  {
    $set: {
      actions: {
        $map: {
          input: "$actions",
          in: {
            $mergeObjects: [
              "$$this",
              {
                $arrayElemAt: [
                  "$actionUsers",
                  {
                    $indexOfArray: [
                      "$actionUsers",
                      {
                        $eq: [
                          "$$this.added_by",
                          "$_id"
                        ]
                      }
                    ]
                  }
                ]
              }
            ]
          }
        }
      },
      actionUsers: "$$REMOVE"
    }
  }
])

查看它在 playground 示例中的工作原理