mongodb数据库的创建，增删改查

Posted 2022-12-08 cuter、

使用创建数据库

use '数据库名称'  //有就使用，没有就创建

插入，增加数据

db.user.insert("name":"xjt")

展示数据库的表

 show collections

展示表的数据

> db.user.find()
 "_id" : ObjectId("6121d6122a72a5ac17821a1d"), "name" : "xjt" 

查找具体的数据

age:$gte:22,$lte:25//大于等于22,小于等于25
> db.user.find()
 "_id" : ObjectId("6121d9702a72a5ac17821a1f"), "age" : 22 
 "_id" : ObjectId("6121d9b92a72a5ac17821a20"), "age" : 25 
> db.user.find("age":22)//等于
 "_id" : ObjectId("6121d9702a72a5ac17821a1f"), "age" : 22 
> db.user.find(age:$gt:22)//大于 age:$gte:22//大于等于
 "_id" : ObjectId("6121d9b92a72a5ac17821a20"), "age" : 25 
> db.user.find(age:$lt:24)//小于  age:$gle:24//小于等于
 "_id" : ObjectId("6121d9702a72a5ac17821a1f"), "age" : 22 
//模糊查询
> db.user.find("name":/zhangsan/)
//查找以什么开头的模糊查询
>db.user.find("name":/^zhang/)
//查找以什么结尾的模糊查询
>db.user.find("name":/zhang$/)
//查询指定name，age数据
>db.user.find(,name:1)
>db.user.find(,age:1)
>db.user.find("age":$gte:20,age:1)
//查询name为wangwu，age为25
>db.user.find("name":"wangzu","age":25)
//查询前5条数据
>db.user.find().limt(2)
//查询10条以后的数据
>db.user.find().skip(10)
//skip和limt可以链式查询 连接起来查询

排序

//升序
>db.user.find().sort("age":1)
//降序
>db.user.find().sort("age":1)

删除数据库

 > db.dropDatabase()
 "ok" : 1 

删除某一个表(集合)

> db.tokens.drop()
true

连贯操作

查询统计数据库数据条数

> use xjts
switched to db xjts
> for(var i=0;i<99;i++)
... db.user.insert("name":"zhangsan"+i,"age":i)
... ;
> db.user.find().count()
99
> db.user.find(age:$gte:66).count()
33
//第一页
> db.user.find().skip(0).limt(10)
//第二页
> db.user.find().skip(10).limt(10)
> //第三页
(3-1)*10
> db.user.find().skip(20).limt(10)
算法:skip的page-1然后乘以pageSzie，然后limt（pageSize）

or 与查询

> db.user.find($or:[age:22,age:25])
 "_id" : ObjectId("6121f464e9b431717ff1f417"), "name" : "zhangsan22", "age" : 22 
 "_id" : ObjectId("6121f464e9b431717ff1f41a"), "name" : "zhangsan25", "age" : 25 

修改数据

> db.user.update(age:25,$set:age:66666)
WriteResult( "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 )
> db.user.find(age:66666)
 "_id" : ObjectId("6121f464e9b431717ff1f41a"), "name" : "zhangsan25", "age" : 66666 
//添加修改属性
> db.user.update(age:66666,$set:age:655,sex:"男人")))
WriteResult( "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 )                          )
> db.user.find(age:655)
 "_id" : ObjectId("6121f464e9b431717ff1f41a"), "name" : "zhangsan25", "age" : 655, "sex" : "男人" 
//如果没有$set则会重写覆盖这条数据
> db.user.update(age:655,age:888)
WriteResult( "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 )
> db.user.find(age:888)
 "_id" : ObjectId("6121f464e9b431717ff1f41a"), "age" : 888 
//更新多条数据 multi:true
> db.user.update(age:$lte:5,$set:"sex":"男")
WriteResult( "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 )
> db.user.find().limit(5)                          )
 "_id" : ObjectId("6121f464e9b431717ff1f401"), "name" : "zhangsan0", "age" : 0, "sex" : "男" 
 "_id" : ObjectId("6121f464e9b431717ff1f402"), "name" : "zhangsan1", "age" : 1 
 "_id" : ObjectId("6121f464e9b431717ff1f403"), "name" : "zhangsan2", "age" : 2 
 "_id" : ObjectId("6121f464e9b431717ff1f404"), "name" : "zhangsan3", "age" : 3 
 "_id" : ObjectId("6121f464e9b431717ff1f405"), "name" : "zhangsan4", "age" : 4 
> db.user.update(age:$lte:5,$set:"sex":"男",multi:true)
WriteResult( "nMatched" : 6, "nUpserted" : 0, "nModified" : 5 )
> db.user.find().limit(5)                                       )
 "_id" : ObjectId("6121f464e9b431717ff1f401"), "name" : "zhangsan0", "age" : 0, "sex" : "男" 
 "_id" : ObjectId("6121f464e9b431717ff1f402"), "name" : "zhangsan1", "age" : 1, "sex" : "男" 
 "_id" : ObjectId("6121f464e9b431717ff1f403"), "name" : "zhangsan2", "age" : 2, "sex" : "男" 
 "_id" : ObjectId("6121f464e9b431717ff1f404"), "name" : "zhangsan3", "age" : 3, "sex" : "男" 
 "_id" : ObjectId("6121f464e9b431717ff1f405"), "name" : "zhangsan4", "age" : 4, "sex" : "男" 
>

删除数据

//可删除一条或多条
>db.user.remove(age:22)
>db.user.remove(age:$lte:10,justOne:true)
WriteResult( "nRemoved" : 11 )