mongodb - 根据MongoDB中两个日期的差异统计记录

Question

根据下面的文档，我需要统计initial_date和end_date之间的差异大于和小于5分钟并且name = A的记录。

[{
    "_id": 1,
    "name": "A",
    "inicial_date": "2019-01-01 12:00:00",
    "end_date": "2019-01-01 12:01:00"
},{
    "_id": 2,
    "name": "A",
    "inicial_date": "2019-01-01 12:05:00",
    "end_date": "2019-01-01 12:07:00"
},{
    "_id": 3,
    "name": "A",
    "inicial_date": "2019-01-01 12:00:00",
    "end_date": "2019-01-01 12:06:00"
},{
    "_id": 4,
    "name": "A",
    "inicial_date": "2019-01-01 12:04:00",
    "end_date": "2019-01-01 12:05:00"
},
    "_id": 5,
    "name": "A",
    "inicial_date": "2019-01-01 12:10:00",
    "end_date": "2019-01-01 12:20:00"
},{
    "_id": 6,
    "name": "A",
    "inicial_date": "2019-01-01 12:00:00",
    "end_date": "2019-01-01 12:08:00"
},{
    "_id": 7,
    "name": "A",
    "inicial_date": "2019-01-01 13:00:00",
    "end_date": "2019-01-01 13:01:00"
},{
    "_id": 8,
    "name": "B",
    "inicial_date": "2019-01-01 14:00:00",
    "end_date": "2019-01-01 14:09:00"
}]

预期结果：

{
    "less_than_5": 4,
    "greater_than_5": 3
}

Answer 1

好吧，你可以使用聚合查询来做到这一点，

    db.collection.aggregate([
    {
        $match: {
            name: "A"
        }
    },
    {
        // find time difference, the result is in milliseconds
        $project: {
            timeDiffInMilliseconds: {
                $subtract: [
                    {
                        $toDate: "$end_date"
                    },
                    {
                        $toDate: "$inicial_date"
                    }
                ]
            }
        }
    },
    {
        // convert the time difference to minutes
        $project: {
            timeDiffInMinutes: {
                $divide: [
                    "$timeDiffInMilliseconds",
                    60000
                ]
            }
        }
    },
    {
        // check if the number of minutes is greater than 5 mins or not
        $project: {
            timeDiffGreaterThan5Mins: {
                $cond: [
                    {
                        $gt: [
                            "$timeDiffInMinutes",
                            5
                        ]
                    },
                    1,
                    0
                ]
            }
        }
    },
    {
        // group according to greater than 5 minutes or not
        $group: {
            _id: "null",
            greater_than_5: {
                $sum: {
                    $cond: [
                        {
                            $eq: [
                                "$timeDiffGreaterThan5Mins",
                                1
                            ]
                        },
                        1,
                        0
                    ]
                }
            },
            less_than_5: {
                $sum: {
                    $cond: [
                        {
                            $eq: [
                                "$timeDiffGreaterThan5Mins",
                                0
                            ]
                        },
                        1,
                        0
                    ]
                }
            }
        }
    }
])

让它更有效率，

db.collection.aggregate([
  {
    $match: {
      name: "A"
    }
  },
  {
    $project: {
      more_than_5_mins: {
        $cond: [
          {
            $gt: [
              {
                $subtract: [
                  {
                    $toDate: "$end_date"
                  },
                  {
                    $toDate: "$inicial_date"
                  }
                ]
              },
              300000
            ]
          },
          1,
          0
        ]
      }
    }
  },
  {
    $group: {
      _id: "",
      less_than_5: {
        $sum: {
          $cond: [
            {
              $eq: [
                "$more_than_5_mins",
                0
              ]
            },
            1,
            0
          ]
        }
      },
      greater_than_5: {
        $sum: {
          $cond: [
            {
              $eq: [
                "$more_than_5_mins",
                1
              ]
            },
            1,
            0
          ]
        }
      }
    }
  }
])