MongoDB 彙總管道(aggregate)

來源:互聯網
上載者:User

標籤:post   aggregate   count   年齡   函數   css   body   總數   span   

1、彙總函式
  •  查詢總數 .count()
> db.userinfo.count()3> db.userinfo.find(){ "_id" : 1, "name" : "郭大爺", "sex" : "男", "age" : "80" }{ "_id" : 2, "name" : "郭老師", "sex" : "男", "age" : "不詳" }{ "_id" : 3, "name" : "郭少爺", "sex" : "男", "age" : "18" }
2、aggregate() 方法

我們先插入一些測試資料

{     "_id" : ObjectId("5abc960c684781cda6d38027"),     "name" : "郭大爺",     "sex" : "男",     "age" : 80.0,     "skil" : [        "PHP",         "Js",         "MySql",         "Html",         "Css"    ]}{     "_id" : ObjectId("5abc960c684781cda6d38028"),     "name" : "郭大爺",     "sex" : "男",     "age" : 60.0,     "skil" : [        "PHP",         "MySql"    ]}{     "_id" : ObjectId("5abc960c684781cda6d38029"),     "sex" : "女"}{     "_id" : ObjectId("5abc960c684781cda6d3802a"),     "name" : "郭少爺",     "sex" : "男",     "age" : 18.0,     "skil" : [        "Css",         "Java",         "Html"    ]}
  • 求和 

查詢一下所有人年齡的總和

db.userinfo.aggregate([    { $group : {        _id : null,        age_sum : { $sum : "$age" }    }}])

結果

{     "_id" : null,     "age_sum" : 158.0}
  • 平均值
  • 最小值
  • 最大值
  • 擷取第一個文檔
  • 擷取最後一個文檔

MongoDB 彙總管道(aggregate)

相關文章

聯繫我們

該頁面正文內容均來源於網絡整理,並不代表阿里雲官方的觀點,該頁面所提到的產品和服務也與阿里云無關,如果該頁面內容對您造成了困擾,歡迎寫郵件給我們,收到郵件我們將在5個工作日內處理。

如果您發現本社區中有涉嫌抄襲的內容,歡迎發送郵件至: info-contact@alibabacloud.com 進行舉報並提供相關證據,工作人員會在 5 個工作天內聯絡您,一經查實,本站將立刻刪除涉嫌侵權內容。

A Free Trial That Lets You Build Big!

Start building with 50+ products and up to 12 months usage for Elastic Compute Service

  • Sales Support

    1 on 1 presale consultation

  • After-Sales Support

    24/7 Technical Support 6 Free Tickets per Quarter Faster Response

  • Alibaba Cloud offers highly flexible support services tailored to meet your exact needs.