mongodb 基础查询使用

环境安装
https://blog.csdn.net/qq_42402648/article/details/134932412
net start MongoDB 启动
net stop MongoDB 停止
测试插入数据结构

java 复制代码

{
  "create_time": {
    "$data": "1711244538176"
  },
  "language": "en",
  "create_time01": "1711244538176",
  "source": "ximalaya",
  "time": 848
}

数据基础查询

java 复制代码

	 查询source为ximalaya
	 {"source":"ximalaya"}
	 查询source为ximalaya，language为 zh 
	 {"source":"ximalaya","language":"zh"}
	 查询source为ximalaya，time<300
	 {"source":"ximalaya","time":{"$lt":300}}
	  查询source为ximalaya,language为zh或者ko
	 {"source":"ximalaya","language":{"$in":["jp","ko"]}}
	 查询source为null  false为null,true 不为null
	 {"source":{"$exists":false}}
	 根据time降序 -1降序，1 升序
	 {"time":-1}

聚合查询

java 复制代码

统计language为zh的总数
[
  {
    $match: {
      language: "zh",
    }
  },
  {
      $count: 'language_count'
  }
]

根据source分组统计总数
[
  {
    $group: {
      _id: "$source",
      count: {
        $sum: 1
      }
    }
  }
]
根据source分组统计所有time和
[
  {
    $group: {
      _id: "$source",
      count: {
        $sum: 1,
      },
      time_sum: {
        $sum: "$time",
      },
    },
  },
]
数组文档拆分 ，一拆多行数据
[
  {
    $unwind:  "$tag"
  },
]
关联表查询
[
  {
    $match: {
      source: "qintin",
    },
  },
  {
    $lookup: {
      from: "base_info_v2",
      localField: "v2_id",
      foreignField: "id",
      as: "v2Info",
    },
  },
]

管道操作符

java 复制代码

 $project 指定输出的字段
[
  {
    $project: {
      sourceName: "$source",
      date:"$time",
    },
  },
]
 $match 添加过滤条件
[
  {
    $match: {
      source:"youtube"
    }
  },
  {
    $project: {
      sourceName: "$source",
      date:"$time",
    },
  },
]
 $count 统计结果总数
[
  {
    $match: {
      source:"youtube"
    }
  },
  {
    $count: 'sourceCount'
  }
]

分组后将输出结果使用project重新命名
[
  {
    $group: {
      _id: "$source",
      count:{
         $sum:1
      }
    }
  },
  {
    $project: {
      source:"$_id",
      count:"$count"
    }
  }
]

根据时间分组（时间格式化）

再根据source分组统计出每天每个来源的总数

将分组后的数据重新命名，再次根据时间分组

最后根据时间升序排序

java 复制代码

[
  {
    $group: {
      _id: {
        date: {
          $dateToString: {
            format: "%Y-%m-%d",
            date: "$create_time",
          },
        },
        source: "$source",
      },
      count: {
        $sum: 1,
      },
    },
  },
  {
    $project: {
      date: "$_id.date",
      source: "$_id.source",
      count: "$count",
    },
  },
  {
    $group: {
      _id: "$date",
      positions: {
        $push: {
          source: "$source",
          count: "$count",
        },
      },
    },
  },
  {
    $sort: {
      _id: 1
    }
  }
]