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mongodb基础
阅读量：5299 次
发布时间：2019-06-14

本文共 15899 字，大约阅读时间需要 52 分钟。

MongoDB在MAC下的安装

  • 安装

huijundeMacBook-Pro:~ huijunzhang$ brew install mongodb  ...  ==> Downloading https://homebrew.bintray.com/bottles/mongodb-3.2.9.el_capitan.bottle.tar.gz  ######################################################################## 100.0%  ==> Pouring mongodb-3.2.9.el_capitan.bottle.tar.gz  ==> Caveats  To have launchd start mongodb now and restart at login:    brew services start mongodb  Or, if you don't want/need a background service you can just run:    mongod --config /usr/local/etc/mongod.conf  ==> Summary  ?  /usr/local/Cellar/mongodb/3.2.9: 17 files, 241.2M

 

  • 启动MongoDB

    上面提示的直接启动mongo的方法

mongod --config /usr/local/etc/mongod.conf

 

具体操作如下：

huijundeMacBook-Pro:~ huijunzhang$ mongod --config /usr/local/etc/mongod.conf &[1] 19869huijundeMacBook-Pro:~ huijunzhang$ mongoMongoDB shell version: 3.2.9connecting to: testWelcome to the MongoDB shell.For interactive help, type "help".For more comprehensive documentation, see    http://docs.mongodb.org/Questions? Try the support group    http://groups.google.com/group/mongodb-userServer has startup warnings: 2016-08-31T09:30:34.820+0800 I CONTROL  [initandlisten] 2016-08-31T09:30:34.820+0800 I CONTROL  [initandlisten] ** WARNING: soft rlimits too low. Number of files is 256, should be at least 1000

 

到此，mongoDB在mac下的安装就完成了

一、基本操作

mongodb中的基本操作无非就是增删改查，看下边

insert：

> db.table_name.insert({
   "name":"zhj","age":20,"province":"henan"})WriteResult({ "nInserted" : 1 })> db.table_name.insert({
   "name":"zjf","age":18,"province":"beijing"})WriteResult({ "nInserted" : 1 })> db.table_name.insert({
   "name":"zg","age":22,"province":"beijing"})WriteResult({ "nInserted" : 1 })

 

mongo不支持批量插入，如果需要批量插入，就使用for循环操作

find：

> db.table_name.find(){ "_id" : ObjectId("57c6364278935e710c61131b"), "name" : "zhj", "age" : 20, "province" : "henan" }{ "_id" : ObjectId("57c6365e78935e710c61131c"), "name" : "zjf", "age" : 18, "province" : "beijing" }{ "_id" : ObjectId("57c6366e78935e710c61131d"), "name" : "zg", "age" : 22, "province" : "beijing" }

 

  • "无关键字","$ne","$gt","$gte","$lt","$lte"

sql | mongo | 说明 | ---|---|---|

|$gt |大于 =|$gte|大于等于 < |$lt |小于 <=|$lte|小于等于 !=|$ne |不等于 ==| |等于

#select * from table_name where age == 20db.table_name.find({
    "age":20})#select * from table_name where age != 20db.table_name.find({
    "age":{$ne:20}})#select * from table_name where age > 20db.table_name.find({
    "age":{$gt:20}})#select * from table_name where age < 20db.table_name.find({
    "age":{$lt:20}})#select * from table_name where age >= 20db.table_name.find({
    "age":{$gte:20}})#select * from table_name where age <= 20db.table_name.find({
    "age":{$lte:20}})# 具体操作如下> db.table_name.find({
   "age":20}){ "_id" : ObjectId("57c6364278935e710c61131b"), "name" : "zhj", "age" : 20, "province" : "henan" }> db.table_name.find({
   "age":{$ne:20}}){ "_id" : ObjectId("57c6365e78935e710c61131c"), "name" : "zjf", "age" : 18, "province" : "beijing" }{ "_id" : ObjectId("57c6366e78935e710c61131d"), "name" : "zg", "age" : 22, "province" : "beijing" }> db.table_name.find({
   "age":{$gt:20}}){ "_id" : ObjectId("57c6366e78935e710c61131d"), "name" : "zg", "age" : 22, "province" : "beijing" }> db.table_name.find({
   "age":{$lt:20}}){ "_id" : ObjectId("57c6365e78935e710c61131c"), "name" : "zjf", "age" : 18, "province" : "beijing" }> db.table_name.find({
   "age":{$gte:20}}){ "_id" : ObjectId("57c6364278935e710c61131b"), "name" : "zhj", "age" : 20, "province" : "henan" }{ "_id" : ObjectId("57c6366e78935e710c61131d"), "name" : "zg", "age" : 22, "province" : "beijing" }> db.table_name.find({
   "age":{$lte:20}}){ "_id" : ObjectId("57c6364278935e710c61131b"), "name" : "zhj", "age" : 20, "province" : "henan" }{ "_id" : ObjectId("57c6365e78935e710c61131c"), "name" : "zjf", "age" : 18, "province" : "beijing" }

 

  • "无关键字" ,"$or", "$in","$nin"
sql mongo 说明
and    
or $or  
in $in  
not in $nin   
db.table_name.find({
   "name":"zhj","province":"henan"})db.table_name.find({$or:[{
    "province":"henan"},{
   "province":"beijing"}]})db.table_name.find({
    "province":{$in:["henan","beijing"]}})db.table_name.find({
    "province":{$nin:["henan","beijing"]}})# 具体操作如下> db.table_name.find({
   "name":"zhj","province":"henan"}){ "_id" : ObjectId("57c6364278935e710c61131b"), "name" : "zhj", "age" : 20, "province" : "henan" }> db.table_name.find({$or:[{
   "province":"henan"},{
   "province":"beijing"}]}){ "_id" : ObjectId("57c6364278935e710c61131b"), "name" : "zhj", "age" : 20, "province" : "henan" }{ "_id" : ObjectId("57c6365e78935e710c61131c"), "name" : "zjf", "age" : 18, "province" : "beijing" }{ "_id" : ObjectId("57c6366e78935e710c61131d"), "name" : "zg", "age" : 22, "province" : "beijing" }> db.table_name.find({
   "province":{$in:["henan","beijing"]}}){ "_id" : ObjectId("57c6364278935e710c61131b"), "name" : "zhj", "age" : 20, "province" : "henan" }{ "_id" : ObjectId("57c6365e78935e710c61131c"), "name" : "zjf", "age" : 18, "province" : "beijing" }{ "_id" : ObjectId("57c6366e78935e710c61131d"), "name" : "zg", "age" : 22, "province" : "beijing" }> db.table_name.find({
   "province":{$nin:["henan","beijing"]}})>

 

  • 正则表达式

匹配以'j'开头，'e'结尾的  db.table_name.find({
    "name":/^j/,"name":/e$/})  > db.table_name.find({
   "name":/^j/,"name":/g$/})  { "_id" : ObjectId("57c6366e78935e710c61131d"), "name" : "zg", "age" : 22, "province" : "beijing" }

 

  • $where

$where中的value就是我们常用的js  # find name='zhj'  db.table_name.find({$where:function(){
   return this.name == 'zhj'}})  # 具体操作如下        > db.table_name.find({$where:function(){
   return this.name == 'zhj'}})  { "_id" : ObjectId("57c6364278935e710c61131b"), "name" : "zhj", "age" : 20, "province" : "henan" }

 

update:

db.table_name.insert({
   "name":"zhj"},{
   "name":"zhj","age":18})

 

  • 整体更新：

    var model = db.table_name.findOne({
         "name":"zhj"})  model.age = 30  db.table_name.update({
          "name":"zhj"},model)  # 具体操作如下  > var model = db.table_name.findOne({
         "name":"zhj"})  > model.age = 30  30  > db.table_name.update({
         "name":"zhj"},model)  WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 })  > db.table_name.find()  { "_id" : ObjectId("57c6364278935e710c61131b"), "name" : "zhj", "age" : 30, "province" : "henan" }  { "_id" : ObjectId("57c6365e78935e710c61131c"), "name" : "zjf", "age" : 18, "province" : "beijing" }  { "_id" : ObjectId("57c6366e78935e710c61131d"), "name" : "zg", "age" : 22, "province" : "beijing" }

     

  • 局部更新：

　　① $inc修改器

$inc也就是increase的缩写，学过sqlserver的同学应该很熟悉，比如我们做一个在线用户状态记录，每次修改会在原有的基础上自增$inc指定的值，如果“文档”中没有此key，则会创建key，下面的例子一看就懂。

# 原数据的age=20，执行完下面语句，age=50，在原来的基础上加了30db.table_name.update({
    "name":"zhj"},{$inc:{
   "age":30}})# 具体操作如下> db.table_name.find(){ "_id" : ObjectId("57c6364278935e710c61131b"), "name" : "zhj", "age" : 30, "province" : "henan" }{ "_id" : ObjectId("57c6365e78935e710c61131c"), "name" : "zjf", "age" : 18, "province" : "beijing" }{ "_id" : ObjectId("57c6366e78935e710c61131d"), "name" : "zg", "age" : 22, "province" : "beijing" }> db.table_name.update({
   "name":"zhj"},{$inc:{
   "age":30}})WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 })> db.table_name.find(){ "_id" : ObjectId("57c6364278935e710c61131b"), "name" : "zhj", "age" : 60, "province" : "henan" }{ "_id" : ObjectId("57c6365e78935e710c61131c"), "name" : "zjf", "age" : 18, "province" : "beijing" }{ "_id" : ObjectId("57c6366e78935e710c61131d"), "name" : "zg", "age" : 22, "province" : "beijing" }

　　② $set修改器

db.table_name.update({
   "name":"zhj"},{$set:{
   "age":30}})# 具体操作如下> db.table_name.update({
   "name":"zhj"},{$set:{
   "age":30}})WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 })> db.table_name.find(){ "_id" : ObjectId("57c6364278935e710c61131b"), "name" : "zhj", "age" : 30, "province" : "henan" }{ "_id" : ObjectId("57c6365e78935e710c61131c"), "name" : "zjf", "age" : 18, "province" : "beijing" }{ "_id" : ObjectId("57c6366e78935e710c61131d"), "name" : "zg", "age" : 22, "province" : "beijing" }

 

  • upsert操作

这个可是mongodb创造出来的“词”，大家还记得update方法的第一次参数是“查询条件”吗？，那么这个upsert操作就是说：如果我没有查到，我就在数据库里面新增一条，其实这样也有好处，就是避免了我在数据库里面判断是update还是add操作，使用起来很简单，将update的第三个参数设为true即可。

db.table_name.update({
   "name":"zhanghj"},{$inc:{
   "age":30}},true)# 具体操作如下> db.table_name.update({
   "name":"zhanghj"},{$inc:{
   "age":30}},true)WriteResult({    "nMatched" : 0,    "nUpserted" : 1,    "nModified" : 0,    "_id" : ObjectId("57c63ef3a34de94e98acbdd7")})> db.table_name.find(){ "_id" : ObjectId("57c6364278935e710c61131b"), "name" : "zhj", "age" : 30, "province" : "henan" }{ "_id" : ObjectId("57c6365e78935e710c61131c"), "name" : "zjf", "age" : 18, "province" : "beijing" }{ "_id" : ObjectId("57c6366e78935e710c61131d"), "name" : "zg", "age" : 22, "province" : "beijing" }{ "_id" : ObjectId("57c63ef3a34de94e98acbdd7"), "name" : "zhanghj", "age" : 30 }

 

  • 批量更新

在mongodb中如果匹配多条，默认的情况下只更新第一条，那么如果我们有需求必须批量更新，那么在mongodb中实现也是很简单的，在update的第四个参数中设为true即可。例子就不举了。

#有第四个参数的全部更新> db.table_name.find(){ "_id" : ObjectId("57c6364278935e710c61131b"), "name" : "zhj", "age" : 30, "province" : "henan" }{ "_id" : ObjectId("57c6365e78935e710c61131c"), "name" : "zjf", "age" : 18, "province" : "beijing" }{ "_id" : ObjectId("57c6366e78935e710c61131d"), "name" : "zg", "age" : 22, "province" : "beijing" }{ "_id" : ObjectId("57c63ef3a34de94e98acbdd7"), "name" : "zhanghj", "age" : 30 }{ "_id" : ObjectId("57c63fa978935e710c61131e"), "name" : "zhj", "age" : 10, "province" : "hubei" }{ "_id" : ObjectId("57c63fb678935e710c61131f"), "name" : "zhj", "age" : 10, "province" : "hebei" }> db.table_name.update({
   "name":"zhj"},{$set:{
   "age":2}},false,true)WriteResult({ "nMatched" : 3, "nUpserted" : 0, "nModified" : 3 })> db.table_name.find(){ "_id" : ObjectId("57c6364278935e710c61131b"), "name" : "zhj", "age" : 2, "province" : "henan" }{ "_id" : ObjectId("57c6365e78935e710c61131c"), "name" : "zjf", "age" : 18, "province" : "beijing" }{ "_id" : ObjectId("57c6366e78935e710c61131d"), "name" : "zg", "age" : 22, "province" : "beijing" }{ "_id" : ObjectId("57c63ef3a34de94e98acbdd7"), "name" : "zhanghj", "age" : 30 }{ "_id" : ObjectId("57c63fa978935e710c61131e"), "name" : "zhj", "age" : 2, "province" : "hubei" }{ "_id" : ObjectId("57c63fb678935e710c61131f"), "name" : "zhj", "age" : 2, "province" : "hebei" }#没有第四个参数的只更新第一条> db.table_name.find(){ "_id" : ObjectId("57c6364278935e710c61131b"), "name" : "zhj", "age" : 2, "province" : "henan" }{ "_id" : ObjectId("57c6365e78935e710c61131c"), "name" : "zjf", "age" : 18, "province" : "beijing" }{ "_id" : ObjectId("57c6366e78935e710c61131d"), "name" : "zg", "age" : 22, "province" : "beijing" }{ "_id" : ObjectId("57c63ef3a34de94e98acbdd7"), "name" : "zhanghj", "age" : 30 }{ "_id" : ObjectId("57c63fa978935e710c61131e"), "name" : "zhj", "age" : 2, "province" : "hubei" }{ "_id" : ObjectId("57c63fb678935e710c61131f"), "name" : "zhj", "age" : 2, "province" : "hebei" }> db.table_name.update({
   "name":"zhj"},{$set:{
   "age":20}},false)WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 })> db.table_name.find(){ "_id" : ObjectId("57c6364278935e710c61131b"), "name" : "zhj", "age" : 20, "province" : "henan" }{ "_id" : ObjectId("57c6365e78935e710c61131c"), "name" : "zjf", "age" : 18, "province" : "beijing" }{ "_id" : ObjectId("57c6366e78935e710c61131d"), "name" : "zg", "age" : 22, "province" : "beijing" }{ "_id" : ObjectId("57c63ef3a34de94e98acbdd7"), "name" : "zhanghj", "age" : 30 }{ "_id" : ObjectId("57c63fa978935e710c61131e"), "name" : "zhj", "age" : 2, "province" : "hubei" }{ "_id" : ObjectId("57c63fb678935e710c61131f"), "name" : "zhj", "age" : 2, "province" : "hebei" }>

 

remove：

db.table_name.remove()

 

二、高级操作

聚合

常见的聚合操作有：count、distinct、group、mapReduce

count

> db.table_name.find(){ "_id" : ObjectId("57c6364278935e710c61131b"), "name" : "zhj", "age" : 20, "province" : "henan" }{ "_id" : ObjectId("57c6365e78935e710c61131c"), "name" : "zjf", "age" : 18, "province" : "beijing" }{ "_id" : ObjectId("57c6366e78935e710c61131d"), "name" : "zg", "age" : 22, "province" : "beijing" }{ "_id" : ObjectId("57c63ef3a34de94e98acbdd7"), "name" : "zhanghj", "age" : 30 }{ "_id" : ObjectId("57c63fa978935e710c61131e"), "name" : "zhj", "age" : 2, "province" : "hubei" }{ "_id" : ObjectId("57c63fb678935e710c61131f"), "name" : "zhj", "age" : 2, "province" : "hebei" }> db.table_name.count()6> db.table_name.count({
   "age":2})2

 

distinct

> db.table_name.distinct("name")[ "zhj", "zjf", "zg", "zhanghj" ]

 

group

在mongodb里面做group操作有点小复杂，不过大家对sql server 里面的group比较熟悉的话还是一眼能看的明白的，其实group操作本质上形成了一种“k-v”模型，就像C#中的Dictionary，好，有了这种思维，我们来看看如何使用group。

下面举的例子就是按照age进行group操作，value为对应age的姓名。下面对这些参数介绍一下：

  • key： 这个就是分组的key，我们这里是对年龄分组。
  • initial: 每组都分享一个”初始化函数“，特别注意：是每一组，比如这个的age=20的value的list分享一个
  • initial函数，age=22同样也分享一个initial函数。

  • $reduce: 这个函数的第一个参数是当前的文档对象，第二个参数是上一次function操作的累计对象，第一次为initial中的{”perosn“：[]}。有多少个文档， $reduce就会调用多少次。

> db.table_name.find(){ "_id" : ObjectId("57c6364278935e710c61131b"), "name" : "zhj", "age" : 20, "province" : "henan" }{ "_id" : ObjectId("57c6365e78935e710c61131c"), "name" : "zjf", "age" : 18, "province" : "beijing" }{ "_id" : ObjectId("57c6366e78935e710c61131d"), "name" : "zg", "age" : 22, "province" : "beijing" }{ "_id" : ObjectId("57c63ef3a34de94e98acbdd7"), "name" : "zhanghj", "age" : 30 }{ "_id" : ObjectId("57c63fa978935e710c61131e"), "name" : "zhj", "age" : 2, "province" : "hubei" }{ "_id" : ObjectId("57c63fb678935e710c61131f"), "name" : "zhj", "age" : 2, "province" : "hebei" }> db.table_name.group({... "key":{
   "age":true},... "initial":{
   "table_name":[]},... "$reduce":function(cur,prev){...    prev.table_name.push(cur.name);... }... })[    {        "age" : 20,        "table_name" : [            "zhj"        ]    },    {        "age" : 18,        "table_name" : [            "zjf"        ]    },    {        "age" : 22,        "table_name" : [            "zg"        ]    },    {        "age" : 30,        "table_name" : [            "zhanghj"        ]    },    {        "age" : 2,        "table_name" : [            "zhj",            "zhj"        ]    }]

看到上面的结果，是不是有点感觉，我们通过age查看到了相应的name人员，不过有时我们可能有如下的要求：

①：想过滤掉age>25一些人员。

②：有时person数组里面的人员太多，我想加上一个count属性标明一下。

针对上面的需求，在group里面还是很好办到的，因为group有这么两个可选参数: condition 和 finalize。

  • condition: 这个就是过滤条件。

  • finalize:这是个函数，每一组文档执行完后，多会触发此方法，那么在每组集合里面加上count也就是它的活了。

> db.table_name.group({... "key":{
   "age":true},... "initial":{
   "table_name":[]},... "$reduce":function(cur,prev){...    prev.table_name.push(cur.name);... },... "finalize":function(out){... out.count=out.table_name.length;... },... "condition":{
   "age":{$gt:18}}... })[    {        "age" : 20,        "table_name" : [            "zhj"        ],        "count" : 1    },    {        "age" : 22,        "table_name" : [            "zg"        ],        "count" : 1    },    {        "age" : 30,        "table_name" : [            "zhanghj"        ],        "count" : 1    }]

 

mapReduce

参见：

游标

mongodb里面的游标有点类似我们说的C#里面延迟执行，比如：

var list=db.person.find();

针对这样的操作，list其实并没有获取到person中的文档，而是申明一个“查询结构”，等我们需要的时候通过for或者next()一次性加载过来，然后让游标逐行读取，当我们枚举完了之后，游标销毁，之后我们在通过list获取时，

发现没有数据返回了。

> var list = db.table_name.find()> list.forEach(function(x){print(x.name)})zhjzjfzgzhanghjzhjzhj> list>

 

当然我们的“查询构造”还可以搞的复杂点，比如分页，排序都可以加进去。

var single=db.table_name.find().sort({
   "name":1}).skip(2).limit(2);

 

那么这样的“查询构造”可以在我们需要执行的时候执行，大大提高了不必要的花销。

 

sql：

db.car_db.count({    "date_create": {        $gte: ISODate("2016-05-23T16:00:00.000+0000"),        $lt: ISODate("2016-05-24T16:00:00.000+0000")    },    'site': 'che168'})

聚合：

db.maiche168_car_info.aggregate(   [     {       $group:         {               _id: "$shop_id",            company_name:{ $first: "$company_name"},            company_address:{ $first: "$company_address"},            province_name:{ $first: "$province_name"},            city_name:{ $first: "$city_name"},            seller_phone:{ $first: "$seller_phone"},            tags:{ $first: "$tags"},            total:{ $sum: 1},         }     }   ])

---

 

转载于:https://www.cnblogs.com/zhjsll/p/5826350.html

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