今天小编跟大家讲解下有关“MongoDB进行查询文档操作实例是怎样的”的内容 ，相信小伙伴们对这个话题应该有所关注吧，小编也收集到了相关资料，希望小伙伴们看了有所帮助。

MongoDB简介

MongoDB 是一个基于分布式文件存储的数据库。由 C++ 语言编写。旨在为 WEB 应用提供可扩展的高性能数据存储解决方案。

MongoDB 是一个介于关系数据库和非关系数据库之间的产品，是非关系数据库当中功能最丰富，最像关系数据库的。

下面给大家介绍MongoDB查询文档操作的实例

先把student删除，再重新插入数据

> db.student.drop()
true
> db.student.insert([{ "_id" : 1, "name" : "zhangsan", "age": 27, "sex": 1 }, { "_id" : 2, "name" : "lisi", "age": 27 } ,{ "_id" : 3, "name" : "wangwu", "age": 30 }, { "_id" : 4, "name" : "zhaoliu", "age": 28 }, { "_id" : 5, "name" : "qianliu", "age": 33 }, { "_id" : 6, "name" : "sunba", "age": 32 }])
BulkWriteResult({
"writeErrors" : [ ],
"writeConcernErrors" : [ ],
"nInserted" : 6,
"nUpserted" : 0,
"nMatched" : 0,
"nModified" : 0,
"nRemoved" : 0,
"upserted" : [ ]
})
> db.student.find()
{ "_id" : 1, "name" : "zhangsan", "age" : 27 }
{ "_id" : 2, "name" : "lisi", "age" : 27 }
{ "_id" : 3, "name" : "wangwu", "age" : 30 }
{ "_id" : 4, "name" : "zhaoliu", "age" : 28 }
{ "_id" : 5, "name" : "qianliu", "age" : 33 }
{ "_id" : 6, "name" : "sunba", "age" : 32 } 

1、查询指定键

db.集合名称.find({查询条件},{指定键})

指定键：1表示显示，0表示不显示，_id默认显示

> db.student.find({},{name:1})
{ "_id" : 1, "name" : "zhangsan" }
{ "_id" : 2, "name" : "lisi" }
{ "_id" : 3, "name" : "wangwu" }
{ "_id" : 4, "name" : "zhaoliu" }
{ "_id" : 5, "name" : "qianliu" }
{ "_id" : 6, "name" : "sunba" }
> db.student.find({},{_id:0, age:0})
{ "name" : "zhangsan", "sex" : 1 }
{ "name" : "lisi" }
{ "name" : "wangwu" }
{ "name" : "zhaoliu" }
{ "name" : "qianliu" }
{ "name" : "sunba" }
> db.student.find({},{_id:0, name:1})
{ "name" : "zhangsan" }
{ "name" : "lisi" }
{ "name" : "wangwu" }
{ "name" : "zhaoliu" }
{ "name" : "qianliu" }
{ "name" : "sunba" } 

2、各种查询方式

$lt:
$gte:>=
$ne:!=
> db.student.find({age:{$lt:30}})
{ "_id" : 1, "name" : "zhangsan", "age" : 27, "sex" : 1 }
{ "_id" : 2, "name" : "lisi", "age" : 27 }
{ "_id" : 4, "name" : "zhaoliu", "age" : 28 }
> db.student.find({age:{$ne:27}})
{ "_id" : 3, "name" : "wangwu", "age" : 30 }
{ "_id" : 4, "name" : "zhaoliu", "age" : 28 }
{ "_id" : 5, "name" : "qianliu", "age" : 33 }
{ "_id" : 6, "name" : "sunba", "age" : 32 } 

$in:包含

$nin:不包含

> db.student.find({age:{$in:[27,28]}})
{ "_id" : 1, "name" : "zhangsan", "age" : 27, "sex" : 1 }
{ "_id" : 2, "name" : "lisi", "age" : 27 }
{ "_id" : 4, "name" : "zhaoliu", "age" : 28 }
> db.student.find({age:{$nin:[27,28]}})
{ "_id" : 3, "name" : "wangwu", "age" : 30 }
{ "_id" : 5, "name" : "qianliu", "age" : 33 }
{ "_id" : 6, "name" : "sunba", "age" : 32 } 

$or:或者

> db.student.find({$or:[{age:{$lt:29}}, {name:"sunba"}]})
{ "_id" : 1, "name" : "zhangsan", "age" : 27, "sex" : 1 }
{ "_id" : 2, "name" : "lisi", "age" : 27 }
{ "_id" : 4, "name" : "zhaoliu", "age" : 28 }
{ "_id" : 6, "name" : "sunba", "age" : 32 } 

null:空值

> db.student.find({sex: null})
{ "_id" : 2, "name" : "lisi", "age" : 27 }
{ "_id" : 3, "name" : "wangwu", "age" : 30 }
{ "_id" : 4, "name" : "zhaoliu", "age" : 28 }
{ "_id" : 5, "name" : "qianliu", "age" : 33 }
{ "_id" : 6, "name" : "sunba", "age" : 32 } 

$type:键是某种类型的

double:1
string:2
...

> db.student.insert({_id:7, name:7, age:70})
WriteResult({ "nInserted" : 1 })
> db.student.find({name: {$type: 2}})
{ "_id" : 1, "name" : "zhangsan", "age" : 27, "sex" : 1 }
{ "_id" : 2, "name" : "lisi", "age" : 27 }
{ "_id" : 3, "name" : "wangwu", "age" : 30 }
{ "_id" : 4, "name" : "zhaoliu", "age" : 28 }
{ "_id" : 5, "name" : "qianliu", "age" : 33 }
{ "_id" : 6, "name" : "sunba", "age" : 32 }
> db.student.find({name: {$type: 1}})
{ "_id" : 7, "name" : 7, "age" : 70 } 

正则表达式

> db.student.find({name: /si\b/})
{ "_id" : 2, "name" : "lisi", "age" : 27 } 

db.集合名称.findOne({查询条件},{指定键})
查询出符合条件的第一条数据

> db.student.findOne()
{ "_id" : 1, "name" : "zhangsan", "age" : 27, "sex" : 1 } 

db.集合名称.find({查询条件},{指定键}).limit(数字)
查询前几条数据

> db.student.find().limit(3)
{ "_id" : 1, "name" : "zhangsan", "age" : 27, "sex" : 1 }
{ "_id" : 2, "name" : "lisi", "age" : 27 }
{ "_id" : 3, "name" : "wangwu", "age" : 30 } 

db.集合名称.find({查询条件},{指定键}).skip(数字)
跳过前几条数据

> db.student.find().skip(2)
{ "_id" : 3, "name" : "wangwu", "age" : 30 }
{ "_id" : 4, "name" : "zhaoliu", "age" : 28 }
{ "_id" : 5, "name" : "qianliu", "age" : 33 }
{ "_id" : 6, "name" : "sunba", "age" : 32 }
{ "_id" : 7, "name" : 7, "age" : 70 } 

可以使用limit()和skip()实现分页

> db.student.find().skip(0).limit(3)
{ "_id" : 1, "name" : "zhangsan", "age" : 27, "sex" : 1 }
{ "_id" : 2, "name" : "lisi", "age" : 27 }
{ "_id" : 3, "name" : "wangwu", "age" : 30 }
> db.student.find().skip(3).limit(3)
{ "_id" : 4, "name" : "zhaoliu", "age" : 28 }
{ "_id" : 5, "name" : "qianliu", "age" : 33 }
{ "_id" : 6, "name" : "sunba", "age" : 32 }
> db.student.find().skip(6).limit(3)
{ "_id" : 7, "name" : 7, "age" : 70 } 

db.集合名称.find().sort({键:数字})
数字为1表示升序，数字为2表示降序

> db.student.find().sort({age:1})
{ "_id" : 1, "name" : "zhangsan", "age" : 27, "sex" : 1 }
{ "_id" : 2, "name" : "lisi", "age" : 27 }
{ "_id" : 4, "name" : "zhaoliu", "age" : 28 }
{ "_id" : 3, "name" : "wangwu", "age" : 30 }
{ "_id" : 6, "name" : "sunba", "age" : 32 }
{ "_id" : 5, "name" : "qianliu", "age" : 33 }
{ "_id" : 7, "name" : 7, "age" : 70 }
> db.student.find().sort({age:1, _id:-1})
{ "_id" : 2, "name" : "lisi", "age" : 27 }
{ "_id" : 1, "name" : "zhangsan", "age" : 27, "sex" : 1 }
{ "_id" : 4, "name" : "zhaoliu", "age" : 28 }
{ "_id" : 3, "name" : "wangwu", "age" : 30 }
{ "_id" : 6, "name" : "sunba", "age" : 32 }
{ "_id" : 5, "name" : "qianliu", "age" : 33 }
{ "_id" : 7, "name" : 7, "age" : 70 } 

以上就是关于“MongoDB进行查询文档操作实例是怎样的”的介绍了，感谢各位的阅读，希望这篇文章能帮助大家解决问题。如果想要了解更多知识，欢迎关注群英网络，小编每天都会为大家更新不同的知识。

免责声明：本站发布的内容（图片、视频和文字）以原创、转载和分享为主，文章观点不代表本网站立场，如果涉及侵权请联系站长邮箱：mmqy2019@163.com进行举报，并提供相关证据，查实之后，将立刻删除涉嫌侵权内容。

猜你喜欢

• MongoDB安装方式有几种，卸载操作又是怎样

  mongoDB是一个非常不错的数据库，最近也正在学习mongoDB，在使用一个数据库前必不可少的就是安装和卸载，所以下面这篇文章主要给大家介绍了关于Mac系统中mongoDB安装与卸载的相关资料，需要的朋友可以参考借鉴，下面来一起看看吧。

• Linux服务器下如何对mongodb环境配置

  这篇文章主要介绍了在Linux服务器中配置mongodb环境的步骤，具有一定的参考价值，感兴趣的小伙伴们可以参考一下

• MongoD动态添加字段怎样实现，用到哪些知识点

  MongoDB动态添加字段的方法小编在下列文章中给大家已经讲解的非常详细了，需要的朋友不妨自行阅读查看，希望这篇文章对你日后不管是工作还是学习能提供到帮助。

• 新手怎么掌握MongoDB文档操作，有哪些方法

  下面小编就为大家带来一篇MongoDB数据库文档操作方法(必看篇)。小编觉得挺不错的，现在就分享给大家，也给大家做个参考。一起跟随小编过来看看吧

• MongoDB中怎样创建数据库runoob

  MongoDB 创建数据库 语法 MongoDB 创建数据库的语法格式如下： use DATABASE_NAME 如果数据库不存在，则创建数据库，否则切换到指定数据库。 实例 以下实例我们创建了数据库 runoob: > use runoob switched to db runoob > db runoob > 如果你想查看所有数据库，可以使用 show dbs 命令： > show dbs admin..