MongoDB中常用的find

接着前一篇文章，下面主要介绍一下MongoDB中常用的find操作。

先打开MongoDB shell，通过下面一组命令插入一些数据。

 post1 = {"title":"learn MongoDB", "author":"Wilber", "date":new Date(), "score":}

 post2 = {"title":"learn English", "author":"Will", "date":new Date(), "score":}

 post3 = {"title":"learn C#", "author":"Li", "date":new Date(), "score":}

 post4 = {"title":"learn SQL", "author":"July", "date":new Date(), "score":}

 post5 = {"title":"learn Node", "author":"Wilber", "date":new Date(), "score":}

 db.blog.posts.insert(post1)

 db.blog.posts.insert(post2)

 db.blog.posts.insert(post3)

 db.blog.posts.insert(post4)

 db.blog.posts.insert(post5)

 users1 = ["Wilber", "Will", "June"]

 users2 = ["Will", "July", "Wilber"]

 users3 = ["James", "Jack", "Will"]

 db.blog.users.insert({"users":users1})

 db.blog.users.insert({"users":users2})

 db.blog.users.insert({"users":users3})

find（arg1，arg2）简介

find查询会返回一个Collection中文档的子集。关于find的两个参数，arg1表示匹配条件，arg2可以指定要返回的键。

直接上例子，对于arg2，可以通过设置值为0，来控制那些键不要显示

 > db.blog.posts.find({"author":"Will"})

 { "_id" : ObjectId("5479c9f2421b7f1536cfb208"), "title" : "learn English", "author" : "Will", "date" : ISODate("2014-11-

 29T13::.959Z"), "score" : 95 }

 > db.blog.posts.find({}, {"title":, "score":})

 { "_id" : ObjectId("5479c9f2421b7f1536cfb207"), "title" : "learn MongoDB", "score" :  }

 { "_id" : ObjectId("5479c9f2421b7f1536cfb208"), "title" : "learn English", "score" :  }

 { "_id" : ObjectId("5479c9f2421b7f1536cfb209"), "title" : "learn C#", "score" :  }

 { "_id" : ObjectId("5479c9f2421b7f1536cfb20a"), "title" : "learn SQL", "score" :  }

 { "_id" : ObjectId("5479c9f4421b7f1536cfb20b"), "title" : "learn Node", "score" :  }

 > db.blog.posts.find({}, {"date": })

 { "_id" : ObjectId("5479c9f2421b7f1536cfb207"), "title" : "learn MongoDB", "author" : "Wilber", "score" :  }

 { "_id" : ObjectId("5479c9f2421b7f1536cfb208"), "title" : "learn English", "author" : "Will", "score" :  }

 { "_id" : ObjectId("5479c9f2421b7f1536cfb209"), "title" : "learn C#", "author" : "Li", "score" :  }

 { "_id" : ObjectId("5479c9f2421b7f1536cfb20a"), "title" : "learn SQL", "author" : "July", "score" :  }

 { "_id" : ObjectId("5479c9f4421b7f1536cfb20b"), "title" : "learn Node", "author" : "Wilber", "score" :  }

常用查询条件

比较条件：$gt,$gte,$lt,$lte,$ne

 > db.blog.posts.find({"score":{"$gte":,"$lt":}})

 { "_id" : ObjectId("5479c9f2421b7f1536cfb207"), "title" : "learn MongoDB", "author" : "Wilber", "date" : ISODate("2014-1

 -29T13::.939Z"), "score" : 90 }

 { "_id" : ObjectId("5479c9f4421b7f1536cfb20b"), "title" : "learn Node", "author" : "Wilber", "date" : ISODate("2014-11-2

 9T13::.999Z"), "score" : 93 }

 > db.blog.posts.find({"author":{"$ne":"July"}})

 { "_id" : ObjectId("5479c9f2421b7f1536cfb207"), "title" : "learn MongoDB", "author" : "Wilber", "date" : ISODate("2014-1

 -29T13::.939Z"), "score" : 90 }

 { "_id" : ObjectId("5479c9f2421b7f1536cfb208"), "title" : "learn English", "author" : "Will", "date" : ISODate("2014-11-

 29T13::.959Z"), "score" : 95 }

 { "_id" : ObjectId("5479c9f2421b7f1536cfb209"), "title" : "learn C#", "author" : "Li", "date" : ISODate("2014-11-29T13:2

 :.979Z"), "score" : 80 }

 { "_id" : ObjectId("5479c9f4421b7f1536cfb20b"), "title" : "learn Node", "author" : "Wilber", "date" : ISODate("2014-11-2

 9T13::.999Z"), "score" : 93 }

 >

包含条件：$in,$nin

 > db.blog.posts.find({"author":{"$in":["Wilber","Will"]}})

 { "_id" : ObjectId("5479c9f2421b7f1536cfb207"), "title" : "learn MongoDB", "author" : "Wilber", "date" : ISODate("2014-1

 -29T13::.939Z"), "score" : 90 }

 { "_id" : ObjectId("5479c9f2421b7f1536cfb208"), "title" : "learn English", "author" : "Will", "date" : ISODate("2014-11-

 29T13::.959Z"), "score" : 95 }

 { "_id" : ObjectId("5479c9f4421b7f1536cfb20b"), "title" : "learn Node", "author" : "Wilber", "date" : ISODate("2014-11-2

 9T13::.999Z"), "score" : 93 }

 > db.blog.posts.find({"author":{"$nin":["Wilber","Will"]}})

 { "_id" : ObjectId("5479c9f2421b7f1536cfb209"), "title" : "learn C#", "author" : "Li", "date" : ISODate("2014-11-29T13:2

 :.979Z"), "score" : 80 }

 { "_id" : ObjectId("5479c9f2421b7f1536cfb20a"), "title" : "learn SQL", "author" : "July", "date" : ISODate("2014-11-29T1

 ::.989Z"), "score" : 70 }

 >

或操作：$or

 > db.blog.posts.find({"$or":[{"author":"Wilber"}, {"score":{"$gt":}}]})

 { "_id" : ObjectId("5479c9f2421b7f1536cfb207"), "title" : "learn MongoDB", "author" : "Wilber", "date" : ISODate("2014-1

 -29T13::.939Z"), "score" : 90 }

 { "_id" : ObjectId("5479c9f2421b7f1536cfb208"), "title" : "learn English", "author" : "Will", "date" : ISODate("2014-11-

 29T13::.959Z"), "score" : 95 }

 { "_id" : ObjectId("5479c9f4421b7f1536cfb20b"), "title" : "learn Node", "author" : "Wilber", "date" : ISODate("2014-11-2

 9T13::.999Z"), "score" : 93 }

 >

limit(),skip(),sort()

 > db.blog.posts.find().limit()

 { "_id" : ObjectId("5479c9f2421b7f1536cfb207"), "title" : "learn MongoDB", "author" : "Wilber", "date" : ISODate("2014-1

 -29T13::.939Z"), "score" : 90 }

 { "_id" : ObjectId("5479c9f2421b7f1536cfb208"), "title" : "learn English", "author" : "Will", "date" : ISODate("2014-11-

 29T13::.959Z"), "score" : 95 }

 > db.blog.posts.find().skip()

 { "_id" : ObjectId("5479c9f2421b7f1536cfb208"), "title" : "learn English", "author" : "Will", "date" : ISODate("2014-11-

 29T13::.959Z"), "score" : 95 }

 { "_id" : ObjectId("5479c9f2421b7f1536cfb209"), "title" : "learn C#", "author" : "Li", "date" : ISODate("2014-11-29T13:2

 :.979Z"), "score" : 80 }

 { "_id" : ObjectId("5479c9f2421b7f1536cfb20a"), "title" : "learn SQL", "author" : "July", "date" : ISODate("2014-11-29T1

 ::.989Z"), "score" : 70 }

 { "_id" : ObjectId("5479c9f4421b7f1536cfb20b"), "title" : "learn Node", "author" : "Wilber", "date" : ISODate("2014-11-2

 9T13::.999Z"), "score" : 93 }

 > db.blog.posts.find().sort({"athor":,"score":-})

 { "_id" : ObjectId("5479c9f2421b7f1536cfb208"), "title" : "learn English", "author" : "Will", "date" : ISODate("2014-11-

 29T13::.959Z"), "score" : 95 }

 { "_id" : ObjectId("5479c9f4421b7f1536cfb20b"), "title" : "learn Node", "author" : "Wilber", "date" : ISODate("2014-11-2

 9T13::.999Z"), "score" : 93 }

 { "_id" : ObjectId("5479c9f2421b7f1536cfb207"), "title" : "learn MongoDB", "author" : "Wilber", "date" : ISODate("2014-1

 -29T13::.939Z"), "score" : 90 }

 { "_id" : ObjectId("5479c9f2421b7f1536cfb209"), "title" : "learn C#", "author" : "Li", "date" : ISODate("2014-11-29T13:2

 :.979Z"), "score" : 80 }

 { "_id" : ObjectId("5479c9f2421b7f1536cfb20a"), "title" : "learn SQL", "author" : "July", "date" : ISODate("2014-11-29T1

 ::.989Z"), "score" : 70 }

 >

数组的查询

$all：通过多个元素匹配数组
支持“键.下标”方式的匹配
支持$size的方式匹配

 > db.blog.users.find({"users":"Will"})

 { "_id" : ObjectId("5479d03d421b7f1536cfb20c"), "users" : [  "Wilber",  "Will",  "June" ] }

 { "_id" : ObjectId("5479d03d421b7f1536cfb20d"), "users" : [  "Will",  "July",  "Wilber" ] }

 { "_id" : ObjectId("5479d03d421b7f1536cfb20e"), "users" : [  "James",  "Jack",  "Will" ] }

 > db.blog.users.find({"users": {"$all": ["Wilber", "Will"]}})

 { "_id" : ObjectId("5479d03d421b7f1536cfb20c"), "users" : [  "Wilber",  "Will",  "June" ] }

 { "_id" : ObjectId("5479d03d421b7f1536cfb20d"), "users" : [  "Will",  "July",  "Wilber" ] }

 > db.blog.users.find({"users": ["Wilber", "Will"]})

 > db.blog.users.find({"users.2":"Will"})

 { "_id" : ObjectId("5479d03d421b7f1536cfb20e"), "users" : [  "James",  "Jack",  "Will" ] }

 > db.blog.users.find({"users":{"$size":}})

 { "_id" : ObjectId("5479d03d421b7f1536cfb20c"), "users" : [  "Wilber",  "Will",  "June" ] }

 { "_id" : ObjectId("5479d03d421b7f1536cfb20d"), "users" : [  "Will",  "July",  "Wilber" ] }

 { "_id" : ObjectId("5479d03d421b7f1536cfb20e"), "users" : [  "James",  "Jack",  "Will" ] }

 >

null的含义

 > post5.z = null

 null

 > db.blog.posts.update({"title":"learn Node"}, post5)

 > db.blog.posts.find({"z":null})

 { "_id" : ObjectId("5479c9f2421b7f1536cfb207"), "title" : "learn MongoDB", "author" : "Wilber", "date" : ISODate("2014-1

 -29T13::.939Z"), "score" : 90 }

 { "_id" : ObjectId("5479c9f2421b7f1536cfb208"), "title" : "learn English", "author" : "Will", "date" : ISODate("2014-11-

 29T13::.959Z"), "score" : 95 }

 { "_id" : ObjectId("5479c9f2421b7f1536cfb209"), "title" : "learn C#", "author" : "Li", "date" : ISODate("2014-11-29T13:2

 :.979Z"), "score" : 80 }

 { "_id" : ObjectId("5479c9f2421b7f1536cfb20a"), "title" : "learn SQL", "author" : "July", "date" : ISODate("2014-11-29T1

 ::.989Z"), "score" : 70 }

 { "_id" : ObjectId("5479c9f4421b7f1536cfb20b"), "title" : "learn Node", "author" : "Wilber", "date" : ISODate("2014-11-2

 9T13::.999Z"), "score" : 93, "z" : null }

 > db.blog.posts.find({"z":{"$in":[null], "$exists": true}})

 { "_id" : ObjectId("5479c9f4421b7f1536cfb20b"), "title" : "learn Node", "author" : "Wilber", "date" : ISODate("2014-11-2

 9T13::.999Z"), "score" : 93, "z" : null }

 >

Ps:可以通过以下链接的到例子中的shell命令。

http://files.cnblogs.com/wilber2013/find.js

MongoDB中常用的find的更多相关文章

mongoDB的常用语法
安装: 到mongodb官网下载安装包或者压缩包:https://www.mongodb.com/download-center?jmp=nav 1.如果是msi包的话则点击按步骤安装,如果是压缩包的 ...
在MongoDB中实现聚合函数（转）
随着组织产生的数据爆炸性增长,从GB到TB,从TB到PB,传统的数据库已经无法通过垂直扩展来管理如此之大数据.传统方法存储和处理数据的成本将会随着数据量增长而显著增加.这使得很多组织都在寻找一种经济的 ...
mongodb的常用操作
对于nosql之前工作中有用到bekerlydb,最近开始了解mongodb,先简单写下mongodb的一些常用操作,当是个总结: 1.mongodb使用数据库(database)和集合(collec ...
MongoDB实战指南(五)：MongoDB中的聚集分析
聚集操作是对数据进行分析的有效手段.MongoDB主要提供了三种对数据进行分析计算的方式:管道模式聚集分析,MapReduce聚集分析,简单函数和命令的聚集分析. 1. 管道模式进行聚集这里所说的管 ...
MongoDB中的分组
一.MongoDB中的Count函数.Distinct函数以及分组准备工作,插入一个班级的文档 > for(var i=0;i<10;i++){ ... db.Classes.inser ...
使用highcharts显示mongodb中的数据
1.mongodb数据表相关 # 显示数据库 show dbs # 数据库 use ceshi # 显示表 show tables # 创建集合 db.createCollection('infoB' ...
【mongodb系统学习之八】mongodb shell常用操作
八.mongodb shell常用基础操作(每个语句后可以加分号,也可以不加,看情况定(有的工具中可以不加),最好是加): 1).进入shell操作界面:mongo,上边已有演示: 2).查看当前使 ...
Mongodb中 Documents文档说明
mongodb使用BSON格式存储数据记录. 如下图: 文档结构文档有键值对组成, 有以下结构: { field1: value1, field2: value2, ... ...
MongoDB的常用命令和增查改删
数据库操作 Mongodb MySQL 查询库 show databases | show dbs show databases 选中库 use databaseName use databaseNa ...

随机推荐

Encapsulating Data 数据封装
Objective-C中类的封装本质上其他OO语言没什么区别,不过在概念和书写表达上差异还是比较大的, Property属性这里的Property并不是简单的类成员变量,而是OC中特有的可以为编译器 ...
关于Unity中混合模式、Alpha测试、深度测试、通道遮罩、面剔除的使用----渲染通道通用指令(二)
混合模式着色完成后,需要把颜色混合到帧缓冲区里面,涉及到源和目标. 1:在所有计算完成后,决定当前的计算结果输出到帧缓冲区时,如何混合源和目标,通常用来绘制半透明的物体;2: Blend Off 关 ...
原创：如何实现在Excel通过循环语句设置指定行的格式
原创:如何实现在Excel通过循环语句设置指定行的格式一.需求: 想让excel的某些行(比如3的倍数的行)字体变成5号字如何整: 二.实现: Sub code() To Range(" ...
(笔记)Mysql命令insert into：向表中插入数据（记录）
insert into命令用于向表中插入数据. insert into命令格式:insert into <表名> [(<字段名1>[,..<字段名n > ])] v ...
(笔记)Linux延时及时间函数总结
一. 基础知识1.时间类型.Linux下常用的时间类型有4个:time_t,struct timeval,struct timespec,struct tm.(1)time_t是一个长整型,一般用来表 ...
python2 python3 字符串编码格式处理
使用python的ctypes调用c语言中的函数,传入字符串,打印输出异常.解决方法记录于此. 参考连接: http://blog.csdn.net/u011546806/article/detail ...
模式识别之bayes---bayes 简单天气预测实现实例
Bayes Classifier 分类在模式识别的实际应用中,贝叶斯方法绝非就是post正比于prior*likelihood这个公式这么简单,一般而言我们都会用正态分布拟合likelihood来实 ...
Android多国语言的value文件夹命名方式
在res目錄下建立不同名稱的values文件來調用不同的語言包Values文件匯總如下:中文(中國):values-zh-rCN中文(台灣):values-zh-rTW中文(香港):values-zh ...
Windows 7运行命令大全
Windows 7运行命令大全,小编整理了常用的45个Win7运行命令分享给大家:1.cleanmgr:打开磁盘清理工具 2.compmgmt.msc:计算机管理 3.conf:启动系统配置实用程序 ...
猫猫学iOS之小知识iOS启动动画_Launch Screen的运用
猫猫分享,必须精品原创文章.欢迎转载.转载请注明:翟乃玉的博客地址:http://blog.csdn.net/u013357243? viewmode=contents 看下效果吧比如新浪微博的 ...

MongoDB中常用的find

find（arg1，arg2）简介

常用查询条件

MongoDB中常用的find的更多相关文章

随机推荐

热门专题