MongoDB

01 认识MongoDB

MongoDB简介

       基于分布式文件存储的开源数据库系统。旨在为WEB应用提供可扩展的高性能数据存储解决方案。将数据存储为一个文档，文档类似于 Json格式，MongoDB是非关系型数据库，Json格式和字典格式很类似
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     {
          name:"aa" , 
           age:100，
           address:{city:"cs"，country:"china"}
       }

MongoDB数据模型

02 库、集合操作

库与表操作

进入数据库:     mongo                                 
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退出:        exit
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显示所有库：   show dbs                          
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切换/创建数据库：use 数据库名称      
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> use my_db
> switched to db my_db
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创建集合：          db.createCollection('name')      #里面是字符串
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> db.createCollection('student')
> { "ok" : 1 }
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显示当前数据库的集合：  show collections      #只有里面有数据的库才能查到，如果里面没有数据 ，即便你已经创建了，你也show查不到
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> show collections
> student
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查看当前所在库：     db                                      
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删除集合：        db.集合名称.drop()
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删除库：            db.dropDatabase()     #进入以后才能删除，删除的也就是打开的那个库

03 文档(数据)操作

添加文档（数据）:db.集合名称.insert(document)

添加一条文档 db.students.insert({name:'xiaoming',age:18})

db.students.insert({name:'xiaoming',age:18}) WriteResult({ "nInserted" : 1 }) db.students.insert({name:'qqq',age:22}) WriteResult({ "nInserted" : 1 }) db.students.insert({name:'aaa',age:55}) WriteResult({ "nInserted" : 1 }) db.students.insert({name:'zzz',age:23}) WriteResult({ "nInserted" : 1 }) db.students.insert({name:'www',age:18}) WriteResult({ "nInserted" : 1 }) db.students.insert({name:'sss',age:18}) WriteResult({ "nInserted" : 1 }) db.students.insert({name:'ddd',age:20}) WriteResult({ "nInserted" : 1 }) db.students.insert({name:'ccc',age:16}) WriteResult({ "nInserted" : 1 }) db.students.insert({name:'vvv',age:18}) WriteResult({ "nInserted" : 1 }) db.students.insert({name:'rrr',age:20}) WriteResult({ "nInserted" : 1 })

添加多条文档 db.students.insert([{name:'flz',age:20,sex:'男'},{name:'lanqiao',age:30,sex:'男'}])

db.students.insert([{name:'flz',age:20,sex:'男'},{name:'lanqiao',age:30,sex:'男'}]) BulkWriteResult({ "writeErrors" : [ ], "writeConcernErrors" : [ ], "nInserted" : 2, "nUpserted" : 0, "nMatched" : 0, "nModified" : 0, "nRemoved" : 0, "upserted" : [ ] })

查询文档（数据）

db.集合名称.find([conditions])

查看集合中全部数据：db.students.find() #这里会自动生成一些东西用来区分数据一样的

db.students.find() { "id" : ObjectId("6223572ecca46b2c9c9f42b0"), "name" : "xiaoming", "age" : 18 } { "id" : ObjectId("6223572ecca46b2c9c9f42b1"), "name" : "qqq", "age" : 22 } { "id" : ObjectId("6223572ecca46b2c9c9f42b2"), "name" : "aaa", "age" : 55 } { "id" : ObjectId("6223572ecca46b2c9c9f42b3"), "name" : "zzz", "age" : 23 } { "id" : ObjectId("6223572ecca46b2c9c9f42b4"), "name" : "www", "age" : 18 } { "id" : ObjectId("6223572ecca46b2c9c9f42b5"), "name" : "sss", "age" : 18 } { "id" : ObjectId("6223572ecca46b2c9c9f42b6"), "name" : "ddd", "age" : 20 } { "id" : ObjectId("6223572ecca46b2c9c9f42b7"), "name" : "ccc", "age" : 16 } { "id" : ObjectId("6223572ecca46b2c9c9f42b8"), "name" : "vvv", "age" : 18 } { "id" : ObjectId("6223572ecca46b2c9c9f42b9"), "name" : "rrr", "age" : 20 }

id也可以自己设置

db.students.insert({"name":'qi',id:1}) WriteResult({ "nInserted" : 1 }) db.students.find() { "id" : ObjectId("6223572ecca46b2c9c9f42b0"), "name" : "xiaoming", "age" : 18 } { "id" : ObjectId("6223572ecca46b2c9c9f42b1"), "name" : "qqq", "age" : 22 } { "id" : ObjectId("6223572ecca46b2c9c9f42b2"), "name" : "aaa", "age" : 55 } { "id" : ObjectId("6223572ecca46b2c9c9f42b3"), "name" : "zzz", "age" : 23 } { "id" : ObjectId("6223572ecca46b2c9c9f42b4"), "name" : "www", "age" : 18 } { "id" : ObjectId("6223572ecca46b2c9c9f42b5"), "name" : "sss", "age" : 18 } { "id" : ObjectId("6223572ecca46b2c9c9f42b6"), "name" : "ddd", "age" : 20 } { "id" : ObjectId("6223572ecca46b2c9c9f42b7"), "name" : "ccc", "age" : 16 } { "id" : ObjectId("6223572ecca46b2c9c9f42b8"), "name" : "vvv", "age" : 18 } { "id" : ObjectId("6223572ecca46b2c9c9f42b9"), "name" : "rrr", "age" : 20 } { "id" : 1, "name" : "qi" }

格式化显示：db.students.find().pretty()

查看满足条件的数据：db.students.find({name:'xiaoming'})

db.students.find({name:'xiaoming'}) { "_id" : ObjectId("6223572ecca46b2c9c9f42b0"), "name" : "xiaoming", "age" : 18 }

噩梦条件

and条件 {$and:[{expression1},{expression1},...]}

or条件 {$or:[{expression1},{expression1},...]}

and和or混用

db.table.find({$or:[{$and:[{sex:'女'},{age:18}]},{$and:[{sex:'男'},{age:{$gt:18}}]}]})

例:

db.students.find({$or:[{name:’xiaoming’},{age:18}]})

操作符 描述

$ne 不等于

$gt 大于

$lt 小于

$gte 大于等于

$lte 小于等于

例子：一写冒号就是字典，必须用{}括起来，操作符也必须用{}括起来

db.students.find({"age":{$gte:18}}) { "id" : ObjectId("6223572ecca46b2c9c9f42b0"), "name" : "xiaoming", "age" : 18 } { "id" : ObjectId("6223572ecca46b2c9c9f42b1"), "name" : "qqq", "age" : 22 } { "id" : ObjectId("6223572ecca46b2c9c9f42b2"), "name" : "aaa", "age" : 55 } { "id" : ObjectId("6223572ecca46b2c9c9f42b3"), "name" : "zzz", "age" : 23 } { "id" : ObjectId("6223572ecca46b2c9c9f42b4"), "name" : "www", "age" : 18 } { "id" : ObjectId("6223572ecca46b2c9c9f42b5"), "name" : "sss", "age" : 18 } { "id" : ObjectId("6223572ecca46b2c9c9f42b6"), "name" : "ddd", "age" : 20 } { "id" : ObjectId("6223572ecca46b2c9c9f42b8"), "name" : "vvv", "age" : 18 } { "_id" : ObjectId("6223572ecca46b2c9c9f42b9"), "name" : "rrr", "age" : 20 }

修改文档（数据）

条件+要修改的东西

db.集合名称.update(<query>,<update>,{multi:<boolean>})

修改一条数据：db.students.update({sex:'男'},{age:20}) #会覆盖掉

db.students.update({name:'aaa'},{age:88}) WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 })

db.students.find() { "id" : ObjectId("6223572ecca46b2c9c9f42b0"), "name" : "xiaoming", "age" : 18 } { "id" : ObjectId("6223572ecca46b2c9c9f42b1"), "name" : "qqq", "age" : 22 } { "id" : ObjectId("6223572ecca46b2c9c9f42b2"), "age" : 88 } { "id" : ObjectId("6223572ecca46b2c9c9f42b3"), "name" : "zzz", "age" : 23 } { "id" : ObjectId("6223572ecca46b2c9c9f42b4"), "name" : "www", "age" : 18 } { "id" : ObjectId("6223572ecca46b2c9c9f42b5"), "name" : "sss", "age" : 18 } { "id" : ObjectId("6223572ecca46b2c9c9f42b6"), "name" : "ddd", "age" : 20 } { "id" : ObjectId("6223572ecca46b2c9c9f42b7"), "name" : "ccc", "age" : 16 } { "id" : ObjectId("6223572ecca46b2c9c9f42b8"), "name" : "vvv", "age" : 18 } { "id" : ObjectId("6223572ecca46b2c9c9f42b9"), "name" : "rrr", "age" : 20 } { "_id" : 1, "name" : "qi" }

指定属性修改：{$set:{age:20}} #只修改其中一部分

db.table.update({name:'xiaoming'},{$set:{age:666,sex:'xx'}})

db.students.update({name:'www'},{$set:{age:60}}) WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 })

db.students.find() { "id" : ObjectId("6223572ecca46b2c9c9f42b0"), "name" : "xiaoming", "age" : 18 } { "id" : ObjectId("6223572ecca46b2c9c9f42b1"), "name" : "qqq", "age" : 22 } { "id" : ObjectId("6223572ecca46b2c9c9f42b2"), "age" : 88 } { "id" : ObjectId("6223572ecca46b2c9c9f42b3"), "name" : "zzz", "age" : 23 } { "id" : ObjectId("6223572ecca46b2c9c9f42b4"), "name" : "www", "age" : 60 } { "id" : ObjectId("6223572ecca46b2c9c9f42b5"), "name" : "sss", "age" : 18 } { "id" : ObjectId("6223572ecca46b2c9c9f42b6"), "name" : "ddd", "age" : 20 } { "id" : ObjectId("6223572ecca46b2c9c9f42b7"), "name" : "ccc", "age" : 16 } { "id" : ObjectId("6223572ecca46b2c9c9f42b8"), "name" : "vvv", "age" : 18 } { "id" : ObjectId("6223572ecca46b2c9c9f42b9"), "name" : "rrr", "age" : 20 } { "_id" : 1, "name" : "qi" }

更新集合中所有满足条件的文档：{multi:true}

db.students.update({sex:'男'},{$set:{sex:'女'}},{multi:true})

db.students.update({sex:'男'},{$set:{sex:'女'}},{multi:true}) WriteResult({ "nMatched" : 2, "nUpserted" : 0, "nModified" : 2 })

db.students.find() { "id" : ObjectId("6223572ecca46b2c9c9f42b0"), "name" : "xiaoming", "age" : 18 } { "id" : ObjectId("6223572ecca46b2c9c9f42b1"), "name" : "qqq", "age" : 22 } { "id" : ObjectId("6223572ecca46b2c9c9f42b2"), "age" : 88 } { "id" : ObjectId("6223572ecca46b2c9c9f42b3"), "name" : "zzz", "age" : 23 } { "id" : ObjectId("6223572ecca46b2c9c9f42b4"), "name" : "www", "age" : 60 } { "id" : ObjectId("6223572ecca46b2c9c9f42b5"), "name" : "sss", "age" : 18 } { "id" : ObjectId("6223572ecca46b2c9c9f42b6"), "name" : "ddd", "age" : 20 } { "id" : ObjectId("6223572ecca46b2c9c9f42b7"), "name" : "ccc", "age" : 16 } { "id" : ObjectId("6223572ecca46b2c9c9f42b8"), "name" : "vvv", "age" : 18 } { "id" : ObjectId("6223572ecca46b2c9c9f42b9"), "name" : "rrr", "age" : 20 } { "id" : 1, "name" : "qi" } { "id" : ObjectId("62236218cca46b2c9c9f42ba"), "name" : "flz", "age" : 20, "sex" : "女" } { "_id" : ObjectId("62236218cca46b2c9c9f42bb"), "name" : "lanqiao", "age" : 30, "sex" : "女" }

删除文档（数据）

db.集合名称.remove(<query>,{justOne:<boolean>})

删除集合中所有的文档：db.table.remove({})

删除集合中满足条件的所有文档 db.table.remove({sex:'男'})

只删除集合中满足条件的第一条文档：{justOne:true}

db.table.remove({sex:'男'},{justOne:true})

04 Python操作mongodb，Python与MogoDB交互

pymongo

安装 pip install pymongo

建立连接：pymongo.MongoClient()

指定数据库：db=client[数据库名]

指定集合：collection=db[集合名]

官方推荐

查找文档：find_one() 查找所有：find()

添加文档：insert_one 添加多条：insert_many()

删除文档：delete_one 删除多条：delete_many()

修改文档：update_one 修改多条：update_many()