node.js - 对象数组中的 MongoDB，仅显示具有指定值的对象

Question

我拥有的 MongoDB 架构:

const userTaskSchema = new mongoose.Schema(
    {
       {...}{..}{...}{..} //Multiple objs above here, I just need help with this userTasks

        userTasks: [
            // Array of tasks with date
            {
                task: {
                    type: String,
                    required: true,
                },
                date: {
                    type: Date,
                    default: Date.now,
                },
                done: {
                    type: Boolean,
                    default: false,
                },
            },
        ],
    },

任务数组如下所示:当前输出

"userTasks": [
                    {
                        "done": true,
                        "_id": "6059c57339d5590b04cb0fec",
                        "task": "abc",
                        "date": "2021-03-23T10:39:47.881Z"
                    },
                    {
                        "done": false,
                        "_id": "6059c57739d5590b04cb0fed",
                        "task": "abc",
                        "date": "2021-03-23T10:39:51.558Z"
                    },
                    {
                        "done": false,
                        "_id": "6059c57839d5590b04cb0fee",
                        "task": "abc",
                        "date": "2021-03-23T10:39:52.528Z"
                    },
                    {
                        "done": false,
                        "_id": "6059c57939d5590b04cb0fef",
                        "task": "abc",
                        "date": "2021-03-23T10:39:53.497Z"
                    },
                    {
                        "done": true,
                        "_id": "6059c57a39d5590b04cb0ff0",
                        "task": "abc",
                        "date": "2021-03-23T10:39:54.323Z"
                    }
                ],

我想要的输出是只有 done : false 值存在的数组，我不想要任何 done : true

我无法更改模式，这是我必须处理的。

我想要的输出:

"userTasks": [
                    {
                        "done": false,
                        "_id": "6059c57739d5590b04cb0fed",
                        "task": "abc",
                        "date": "2021-03-23T10:39:51.558Z"
                    },
                    {
                        "done": false,
                        "_id": "6059c57839d5590b04cb0fee",
                        "task": "abc",
                        "date": "2021-03-23T10:39:52.528Z"
                    },
                    {
                        "done": false,
                        "_id": "6059c57939d5590b04cb0fef",
                        "task": "abc",
                        "date": "2021-03-23T10:39:53.497Z"
                    },
                    ],

我找不到任何查询来获得所需的结果。请帮忙。

Answer 1

演示 - https://mongoplayground.net/p/GBF1aWVu0k7

使用$filter在聚合查询中

$project

db.collection.aggregate({
  "$project": {
    a: 1,
    "userTasks": {
      $filter: {
        input: "$userTasks",
        as: "task",
        cond: { "$eq": [ "$$task.done", true] //this is working for me
        }
      }
    }
  }
})