mongodb使用

回顧mysql

• 所有表的集合 --庫
• 每一組信息 --表
• 每一條信息 --字段

但是在mongodb中

• 作為外層的容器還是叫databses
• 在mongodb中表這個東西已經不存在了而叫做 集合（collection）
• 在mongodb中字段這個東西也不存在了而叫做文檔（document）

mongodb使用

• 連接
  語法：mongo空格127.0.0.1:27017

E:\MongoDB\bin>mongo MongoDB shell version v3.4.15-35-gae53ff0702 connecting to: mongodb://127.0.0.1:27017 MongoDB server version: 3.4.15-35-gae53ff0702 Server has startup warnings: 2019-08-13T14:53:41.467+0800 I CONTROL [initandlisten] 2019-08-13T14:53:41.467+0800 I CONTROL [initandlisten] ** WARNING: Access control is not enabled for the database. 2019-08-13T14:53:41.467+0800 I CONTROL [initandlisten] ** Read and write access to data and configuration is unrestricted. 2019-08-13T14:53:41.467+0800 I CONTROL [initandlisten]

• 操作

查看數據庫:show空格dbs;

> show dbs admin 0.000GB local 0.000GB mgd 0.000GB

切換/新增（如果有就是切換 如果沒有就是新增)數據庫
use 空格 要切換或者新增的庫

> use mgd switched to db mgd

注意新增有問題

> show dbs admin 0.000GB local 0.000GB mgd 0.000GB

當我們輸入一個沒有的庫名的時候本應該是新增 但是當我們輸入之后發現并沒有新增 原因是（其實新增了只是里面沒有集合所以不顯示）

創建集合：
db.要創建的集合名字.insert({k:v})

> db.chuichui.insert({"name":"大錘",age:20,sex:"男"}) WriteResult({ "nInserted" : 1 })

查看集合
show空格collections

> show collections chuichui

刪除庫
必須先切換到你要刪的庫 use空格庫名
db.dropDatabase()

刪除集合
必須先要切換到指定要刪除集合的庫中
db.要刪除的集合名.drop()

> use mgd switched to db mgd > db.chuichui.drop() true > show collections >

基本的外圍操作完了

上面的內容重要程度沒有下面高必須要記住:

1. 要對集合進行增刪改查那么必須要有集合

只創建集合的語法
db.createCollection(“要創建集合的名字”);

> db.createCollection("NO13") { "ok" : 1 }

2. 新增

最單純的新增（基礎語法）
db.要插入的集合名.insert({k:v})

> db.NO13.insert({"name":"王大錘",age:20,sex:"男"}) WriteResult({ "nInserted" : 1 })

為了查看我們是否新增成功 使用查詢語句來查看
db.要查詢的集合.find()

> db.NO13.find() { "_id" : ObjectId("5d53b24708a6149f969e8df2"), "name" : "王大錘", "age" : 20, "sex" : "男" } { "_id" : ObjectId("5d53b2a408a6149f969e8df3"), "name" : "王鐵錘", "age" : 30, "sex" : "男" } { "_id" : ObjectId("5d53b2c308a6149f969e8df4"), "name" : "王木錘", "age" : 16, "sex" : "女" } { "_id" : ObjectId("5d53b2e208a6149f969e8df5"), "name" : "王銅錘", "age" : 18, "sex" : "男" } { "_id" : ObjectId("5d53b2f308a6149f969e8df6"), "name" : "王金錘", "age" : 19, "sex" : "男" } { "_id" : ObjectId("5d53b30a08a6149f969e8df7"), "name" : "王銀錘", "age" : 23, "sex" : "女" }

大家會發現id是自動添加的,比較難記
手工新增id
db.要插入的集合名.insert({"_id":1,k:v})

> db.NO13.insert({"_id":1,"name":"王小錘",age:13,sex:"男"}) WriteResult({ "nInserted" : 1 })

既然是手工指定那么千萬不要重名

3. 多條插入

db.要插入的集合.insert([{k:v},{k:v}])

> db.NO13.insert([{"name":"王鋼錘"},{"name":"王石錘"}]) BulkWriteResult({"writeErrors" : [ ],"writeConcernErrors" : [ ],"nInserted" : 2,"nUpserted" : 0,"nMatched" : 0,"nModified" : 0,"nRemoved" : 0,"upserted" : [ ] })

4. 查詢

按照條件進行查詢

db.要查詢的集合名.find({k:v})

> db.NO13.find({age:18}) { "_id" : ObjectId("5d53b2e208a6149f969e8df5"), "name" : "王銅錘", "age" : 18, "sex" : "男" }

格式化查詢數據
Db.要查詢的數據find({k:v},{k:0/1}) 0不顯示 1顯示

> db.NO13.find({"name":"王金錘"},{"age":1,"_id":0}) { "age" : 19 } > db.NO13.find({"age":20},{"sex":1,"_id":0}) { "sex" : "男" }

查詢匹配更多內容
Db.要查詢的數據.find({查詢的內容1，查詢的內容2···})

> db.NO13.find({"name":"王銀錘",sex:"女"}) { "_id" : ObjectId("5d53b30a08a6149f969e8df7"), "name" : "王銀錘", "age" : 23, "sex" : "女" }

條件查詢
Db.查詢的集合.find({“要查詢的k”:{條件:值}})
條件

• (>) 大于 - $gt
• (<) 小于 - $lt
• (>=) 大于等于 - $gte
• (<= ) 小于等于 - $lte
• (!=) 不等于 - $ne:
  代碼：

> db.NO13.find({"age":{$gt:19}}) { "_id" : ObjectId("5d53b24708a6149f969e8df2"), "name" : "王大錘", "age" : 20, "sex" : "男" } { "_id" : ObjectId("5d53b2a408a6149f969e8df3"), "name" : "王鐵錘", "age" : 30, "sex" : "男" } { "_id" : ObjectId("5d53b30a08a6149f969e8df7"), "name" : "王銀錘", "age" : 23, "sex" : "女" } > db.NO13.find({"age":{$lt:19}}) { "_id" : ObjectId("5d53b2c308a6149f969e8df4"), "name" : "王木錘", "age" : 16, "sex" : "女" } { "_id" : ObjectId("5d53b2e208a6149f969e8df5"), "name" : "王銅錘", "age" : 18, "sex" : "男" } { "_id" : 1, "name" : "王小錘", "age" : 13, "sex" : "男" } > db.NO13.find({"age":{$gte:19}}) { "_id" : ObjectId("5d53b24708a6149f969e8df2"), "name" : "王大錘", "age" : 20, "sex" : "男" } { "_id" : ObjectId("5d53b2a408a6149f969e8df3"), "name" : "王鐵錘", "age" : 30, "sex" : "男" } { "_id" : ObjectId("5d53b2f308a6149f969e8df6"), "name" : "王金錘", "age" : 19, "sex" : "男" } { "_id" : ObjectId("5d53b30a08a6149f969e8df7"), "name" : "王銀錘", "age" : 23, "sex" : "女" } > db.NO13.find({"age":{$lte:19}}) { "_id" : ObjectId("5d53b2c308a6149f969e8df4"), "name" : "王木錘", "age" : 16, "sex" : "女" } { "_id" : ObjectId("5d53b2e208a6149f969e8df5"), "name" : "王銅錘", "age" : 18, "sex" : "男" } { "_id" : ObjectId("5d53b2f308a6149f969e8df6"), "name" : "王金錘", "age" : 19, "sex" : "男" } { "_id" : 1, "name" : "王小錘", "age" : 13, "sex" : "男" } > db.NO13.find({"age":{$ne:19}}) { "_id" : ObjectId("5d53b24708a6149f969e8df2"), "name" : "王大錘", "age" : 20, "sex" : "男" } { "_id" : ObjectId("5d53b2a408a6149f969e8df3"), "name" : "王鐵錘", "age" : 30, "sex" : "男" } { "_id" : ObjectId("5d53b2c308a6149f969e8df4"), "name" : "王木錘", "age" : 16, "sex" : "女" } { "_id" : ObjectId("5d53b2e208a6149f969e8df5"), "name" : "王銅錘", "age" : 18, "sex" : "男" } { "_id" : ObjectId("5d53b30a08a6149f969e8df7"), "name" : "王銀錘", "age" : 23, "sex" : "女" } { "_id" : 1, "name" : "王小錘", "age" : 13, "sex" : "男" } { "_id" : ObjectId("5d53b53b08a6149f969e8df8"), "name" : "王鋼錘" } { "_id" : ObjectId("5d53b53b08a6149f969e8df9"), "name" : "王石錘" }

匹配查詢多個內容
Db.要查詢的集合.find({$or:[{查詢的內容1},{查詢的內容2}]})

> db.NO13.find({$or:[{"name":"王金錘"},{"name":"王鐵錘"}]}) { "_id" : ObjectId("5d53b2a408a6149f969e8df3"), "name" : "王鐵錘", "age" : 30, "sex" : "男" } { "_id" : ObjectId("5d53b2f308a6149f969e8df6"), "name" : "王金錘", "age" : 19, "sex" : "男" }

排序查詢
db.要查詢的集合.find().sort({要排序的內容:-1倒序/1正序})

> db.NO13.find().sort({"age":-1}) { "_id" : ObjectId("5d53b2a408a6149f969e8df3"), "name" : "王鐵錘", "age" : 30, "sex" : "男" } { "_id" : ObjectId("5d53b30a08a6149f969e8df7"), "name" : "王銀錘", "age" : 23, "sex" : "女" } { "_id" : ObjectId("5d53b24708a6149f969e8df2"), "name" : "王大錘", "age" : 20, "sex" : "男" } { "_id" : ObjectId("5d53b2f308a6149f969e8df6"), "name" : "王金錘", "age" : 19, "sex" : "男" } { "_id" : ObjectId("5d53b2e208a6149f969e8df5"), "name" : "王銅錘", "age" : 18, "sex" : "男" } { "_id" : ObjectId("5d53b2c308a6149f969e8df4"), "name" : "王木錘", "age" : 16, "sex" : "女" } { "_id" : 1, "name" : "王小錘", "age" : 13, "sex" : "男" } { "_id" : ObjectId("5d53b53b08a6149f969e8df8"), "name" : "王鋼錘" } { "_id" : ObjectId("5d53b53b08a6149f969e8df9"), "name" : "王石錘" }> db.NO13.find().sort({"age":1}) { "_id" : ObjectId("5d53b53b08a6149f969e8df8"), "name" : "王鋼錘" } { "_id" : ObjectId("5d53b53b08a6149f969e8df9"), "name" : "王石錘" } { "_id" : 1, "name" : "王小錘", "age" : 13, "sex" : "男" } { "_id" : ObjectId("5d53b2c308a6149f969e8df4"), "name" : "王木錘", "age" : 16, "sex" : "女" } { "_id" : ObjectId("5d53b2e208a6149f969e8df5"), "name" : "王銅錘", "age" : 18, "sex" : "男" } { "_id" : ObjectId("5d53b2f308a6149f969e8df6"), "name" : "王金錘", "age" : 19, "sex" : "男" } { "_id" : ObjectId("5d53b24708a6149f969e8df2"), "name" : "王大錘", "age" : 20, "sex" : "男" } { "_id" : ObjectId("5d53b30a08a6149f969e8df7"), "name" : "王銀錘", "age" : 23, "sex" : "女" } { "_id" : ObjectId("5d53b2a408a6149f969e8df3"), "name" : "王鐵錘", "age" : 30, "sex" : "男" }

limit讀取指定數量的數據記錄條數
skip使用skip()方法來跳過指定數量的數據

> db.NO13.find().skip(4) { "_id" : ObjectId("5d53b2f308a6149f969e8df6"), "name" : "王金錘", "age" : 19, "sex" : "男" } { "_id" : ObjectId("5d53b30a08a6149f969e8df7"), "name" : "王銀錘", "age" : 23, "sex" : "女" } { "_id" : 1, "name" : "王小錘", "age" : 13, "sex" : "男" } { "_id" : ObjectId("5d53b53b08a6149f969e8df8"), "name" : "王鋼錘" } { "_id" : ObjectId("5d53b53b08a6149f969e8df9"), "name" : "王石錘" }> db.NO13.find().skip(0).limit(2) { "_id" : ObjectId("5d53b24708a6149f969e8df2"), "name" : "王大錘", "age" : 20, "sex" : "男" } { "_id" : ObjectId("5d53b2a408a6149f969e8df3"), "name" : "王鐵錘", "age" : 30, "sex" : "男" }

返回結果集中的數量count()

> db.NO13.find().count() 9

修改:

>db.collection.update({<query>},{$set:{<update>}},{upsert: <boolean>,multi: <boolean>} )

query:查詢出要修改的數據
update:要修改的數據的值
upsert:可選,這個參數的意思是，如果不存在update的記錄，是否插入objNew,true為插入，默認是false，不插入
multi: 可選，MongoDB 默認是false,只更新找到的第一條記錄，如果這個參數為true,就把按條件查出來多條記錄全部更新
7. 單純的修改

> db.NO13.update({"age":16},{"age":116}) WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 }) > db.NO13.find() { "_id" : ObjectId("5d53b24708a6149f969e8df2"), "name" : "王大錘", "age" : 20, "sex" : "男" } { "_id" : ObjectId("5d53b2a408a6149f969e8df3"), "name" : "王鐵錘", "age" : 30, "sex" : "男" } { "_id" : ObjectId("5d53b2c308a6149f969e8df4"), "age" : 116 } { "_id" : ObjectId("5d53b2e208a6149f969e8df5"), "name" : "王銅錘", "age" : 18, "sex" : "男" } { "_id" : ObjectId("5d53b2f308a6149f969e8df6"), "name" : "王金錘", "age" : 19, "sex" : "男" } { "_id" : ObjectId("5d53b30a08a6149f969e8df7"), "name" : "王銀錘", "age" : 23, "sex" : "女" } { "_id" : 1, "name" : "王小錘", "age" : 13, "sex" : "男" } { "_id" : ObjectId("5d53b53b08a6149f969e8df8"), "name" : "王鋼錘" } { "_id" : ObjectId("5d53b53b08a6149f969e8df9"), "name" : "王石錘" }> db.NO13.update({"age":116},{$set:{"name":"王家小錘爺"}}) WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 }) > db.NO13.find() { "_id" : ObjectId("5d53b24708a6149f969e8df2"), "name" : "王大錘", "age" : 20, "sex" : "男" } { "_id" : ObjectId("5d53b2a408a6149f969e8df3"), "name" : "王鐵錘", "age" : 30, "sex" : "男" } { "_id" : ObjectId("5d53b2c308a6149f969e8df4"), "age" : 116, "name" : "王家小錘爺" } { "_id" : ObjectId("5d53b2e208a6149f969e8df5"), "name" : "王銅錘", "age" : 18, "sex" : "男" } { "_id" : ObjectId("5d53b2f308a6149f969e8df6"), "name" : "王金錘", "age" : 19, "sex" : "男" } { "_id" : ObjectId("5d53b30a08a6149f969e8df7"), "name" : "王銀錘", "age" : 23, "sex" : "女" } { "_id" : 1, "name" : "王小錘", "age" : 13, "sex" : "男" } { "_id" : ObjectId("5d53b53b08a6149f969e8df8"), "name" : "王鋼錘" } { "_id" : ObjectId("5d53b53b08a6149f969e8df9"), "name" : "王石錘" }

修改更多內容

> db.NO13.update({"age":19},{$set:{"sec":"半男不女"}},{multi:true}) WriteResult({ "nMatched" : 2, "nUpserted" : 0, "nModified" : 2 }) > db.NO13.find() { "_id" : ObjectId("5d53b24708a6149f969e8df2"), "name" : "王大錘", "age" : 20, "sex" : "男" } { "_id" : ObjectId("5d53b2a408a6149f969e8df3"), "name" : "王鐵錘", "age" : 30, "sex" : "男" } { "_id" : ObjectId("5d53b2c308a6149f969e8df4"), "age" : 116, "name" : "王家小錘爺" } { "_id" : ObjectId("5d53b2e208a6149f969e8df5"), "age" : 19, "sec" : "半男不女" } { "_id" : ObjectId("5d53b2f308a6149f969e8df6"), "name" : "王金錘", "age" : 19, "sex" : "男", "sec" : "半男不女" } { "_id" : ObjectId("5d53b30a08a6149f969e8df7"), "name" : "王銀錘", "age" : 23, "sex" : "女" } { "_id" : 1, "name" : "王小錘", "age" : 13, "sex" : "男" } { "_id" : ObjectId("5d53b53b08a6149f969e8df8"), "name" : "王鋼錘" } { "_id" : ObjectId("5d53b53b08a6149f969e8df9"), "name" : "王石錘" }

刪除
Db.要刪除的集合.remove({k:v})默認刪除匹配到的所有內容

> db.NO13.remove({"age":19}) WriteResult({ "nRemoved" : 2 }) > db.NO13.find() { "_id" : ObjectId("5d53b24708a6149f969e8df2"), "name" : "王大錘", "age" : 20, "sex" : "男" } { "_id" : ObjectId("5d53b2a408a6149f969e8df3"), "name" : "王鐵錘", "age" : 30, "sex" : "男" } { "_id" : ObjectId("5d53b2c308a6149f969e8df4"), "age" : 116, "name" : "王家小錘爺" } { "_id" : ObjectId("5d53b30a08a6149f969e8df7"), "name" : "王銀錘", "age" : 23, "sex" : "女" } { "_id" : 1, "name" : "王小錘", "age" : 13, "sex" : "男" } { "_id" : ObjectId("5d53b53b08a6149f969e8df8"), "name" : "王鋼錘" } { "_id" : ObjectId("5d53b53b08a6149f969e8df9"), "name" : "王石錘" }

只想刪除一條 justOne

Mongoose是一個node的第三方庫,他的作用就是幫助node更好更高效的連接mongodb

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