MongoDB基本操作

MongoDB 基本操作

當(dāng)前文檔基于 MongoDB server version: 4.0.20

0. MongoDB 特性

用MySQL 和 MongoDB 做比較

1. 數(shù)據(jù)庫操作

在mongoDB中, 若數(shù)據(jù)庫不存在，那么只有在庫中向集合插入數(shù)據(jù)的時(shí)候才會(huì)創(chuàng)建

1.1 用法

查看數(shù)據(jù)庫

show dbs

指定數(shù)據(jù)庫

use Database

查看當(dāng)前數(shù)據(jù)庫

默認(rèn)情況下，當(dāng)前數(shù)據(jù)庫是test

db

刪除數(shù)據(jù)庫

在操作此步驟之前，應(yīng)當(dāng)使用 db 確認(rèn)一下庫名

執(zhí)行dropDatabase() 操作后，當(dāng)前選擇的數(shù)據(jù)庫依然是這個(gè)庫，只不過是在內(nèi)存中而已。

db.dropDatabase()

查看數(shù)據(jù)庫版本

db.version()

查看當(dāng)前庫統(tǒng)計(jì)信息

db.stats()

1.2 例子

查看當(dāng)前有哪些數(shù)據(jù)庫

> show dbs admin 0.000GB blogSystem 0.000GB config 0.000GB local 0.000GB >

查看當(dāng)前數(shù)據(jù)庫

> db test >

創(chuàng)建一個(gè)數(shù)據(jù)庫并且查看

> use LearnDB switched to db LearnDB > > db LearnDB >

刪除數(shù)據(jù)庫

> db.dropDatabase() { "ok" : 1 } >

查看數(shù)據(jù)庫版本

> db.version() 4.0.20 >

查看當(dāng)前庫統(tǒng)計(jì)信息

> db.stats() { "db" : "LearnDB", "collections" : 0, "views" : 0, "objects" : 0, "avgObjSize" : 0, "dataSize" : 0, "storageSize" : 0, "numExtents" : 0, "indexes" : 0, "indexSize" : 0, "fileSize" : 0, "fsUsedSize" : 0, "fsTotalSize" : 0, "ok" : 1 } >

2. 集合操作

默認(rèn)情況下，mongo在插入文檔的時(shí)候，集合默認(rèn)會(huì)被創(chuàng)建

2.1 用法

查看當(dāng)前庫的集合

show Collections

插入單條數(shù)據(jù)

db.CollectionName.insertOne()

插入多條數(shù)據(jù)

db.CollectionName.insertMany()

刪除集合

db.CollectionName.drop()

修改集合名稱

db.CollectionName.renameCollection()

創(chuàng)建集合

db.createCollection()

2.2 例子

插入單條數(shù)據(jù)

> db.stu_info.insertOne({"std_name":"小明","sex":"男","reg_time":Date()}) { "acknowledged" : true, "insertedId" : ObjectId("61d6b4afa5a7b57ea8e0a9db") }

查看當(dāng)前庫的集合

> show collections stu_info >

插入多條數(shù)據(jù)

> db.stu_info.insertMany([{"std_name":"小剛","sex":"男","reg_time":Date()},{"std_name":"小紅","sex":"女","reg_time":Date()}]) { "acknowledged" : true, "insertedIds" : [ ObjectId("61d6b59da5a7b57ea8e0a9dc"), ObjectId("61d6b59da5a7b57ea8e0a9dd") ] } >

刪除集合

> db.stu_info.drop() true >

修改集合名稱

> db.stu_info.renameCollection("stuInfo") { "ok" : 1 } > show collections stuInfo >

創(chuàng)建集合

默認(rèn)情況下，向集合中插入數(shù)據(jù)，會(huì)默認(rèn)創(chuàng)建，還有一種情況，是設(shè)置集合為 容量上限模式 ，則需要提前創(chuàng)建

語法

db.createCollection(, { capped: , autoIndexId: , size: , max: , storageEngine: , validator: , validationLevel: , validationAction: , indexOptionDefaults: , viewOn: , pipeline: , collation: , writeConcern: } )

name: 集合名稱 capped: 若為true,則創(chuàng)建 有上限模式 的集合 size: 設(shè)置上限的最大大小，以字節(jié)為單位，若達(dá)到最大值，則會(huì)刪除舊文檔 max: 允許最大文檔數(shù)，當(dāng)同時(shí)設(shè)置 size 和 max ， 則 size 優(yōu)先級(jí) 大于 max

創(chuàng)建有上限的集合, 允許的條數(shù)為5條, 最大容量為1G

> db.createCollection("std_log",{"capped":true , "size": 1073741824 , "max": 5}) { "ok" : 1 } >

測(cè)試插入數(shù)據(jù)

可以發(fā)現(xiàn)，插入超過5條后，新插入的數(shù)據(jù)，會(huì)刪除舊文檔，然后插入新文檔

> db.std_log.insertMany([{"id":1,"status":true,"time":Date()},{"id":2,"status":false,"time":Date()},{"id":3,"status":true,"time":Date()},{"id":4,"status":true,"time":Date()},{"id":5,"status":false,"time":Date()}]) { "acknowledged" : true, "insertedIds" : [ ObjectId("61d6c44da5a7b57ea8e0aa01"), ObjectId("61d6c44da5a7b57ea8e0aa02"), ObjectId("61d6c44da5a7b57ea8e0aa03"), ObjectId("61d6c44da5a7b57ea8e0aa04"), ObjectId("61d6c44da5a7b57ea8e0aa05") ] } > db.std_log.find() { "_id" : ObjectId("61d6c44da5a7b57ea8e0aa01"), "id" : 1, "status" : true, "time" : "Thu Jan 06 2022 18:28:29 GMT+0800 (CST)" } { "_id" : ObjectId("61d6c44da5a7b57ea8e0aa02"), "id" : 2, "status" : false, "time" : "Thu Jan 06 2022 18:28:29 GMT+0800 (CST)" } { "_id" : ObjectId("61d6c44da5a7b57ea8e0aa03"), "id" : 3, "status" : true, "time" : "Thu Jan 06 2022 18:28:29 GMT+0800 (CST)" } { "_id" : ObjectId("61d6c44da5a7b57ea8e0aa04"), "id" : 4, "status" : true, "time" : "Thu Jan 06 2022 18:28:29 GMT+0800 (CST)" } { "_id" : ObjectId("61d6c44da5a7b57ea8e0aa05"), "id" : 5, "status" : false, "time" : "Thu Jan 06 2022 18:28:29 GMT+0800 (CST)" } > > db.std_log.insertOne({"id":6,"status":false,"time":Date()}) { "acknowledged" : true, "insertedId" : ObjectId("61d6c4b9a5a7b57ea8e0aa07") } > db.std_log.find() { "_id" : ObjectId("61d6c44da5a7b57ea8e0aa02"), "id" : 2, "status" : false, "time" : "Thu Jan 06 2022 18:28:29 GMT+0800 (CST)" } { "_id" : ObjectId("61d6c44da5a7b57ea8e0aa03"), "id" : 3, "status" : true, "time" : "Thu Jan 06 2022 18:28:29 GMT+0800 (CST)" } { "_id" : ObjectId("61d6c44da5a7b57ea8e0aa04"), "id" : 4, "status" : true, "time" : "Thu Jan 06 2022 18:28:29 GMT+0800 (CST)" } { "_id" : ObjectId("61d6c44da5a7b57ea8e0aa05"), "id" : 5, "status" : false, "time" : "Thu Jan 06 2022 18:28:29 GMT+0800 (CST)" } { "_id" : ObjectId("61d6c4b9a5a7b57ea8e0aa07"), "id" : 6, "status" : false, "time" : "Thu Jan 06 2022 18:30:17 GMT+0800 (CST)" } >

3. 查詢操作

3.1 用法

查詢集合文檔條數(shù)

db.CollectionNmae.count()

普通查詢

db.CollectionName.find()

格式化顯示

db.CollectionName.find().pretty()

比較查詢

等于

db.CollectionName.find({k:v})

不等于

db.CollectionName.find({k:{$ne: v})

大于

db.CollectionName.find({k:{$gt: v})

小于

db.CollectionName.find({k:{$lt: v})

大于或等于

db.CollectionName.find({k:{$lte: v})

小于或等于

db.CollectionName.find({k:{$gte: v})

and | or 查詢

and

db.CollectionName.find({k:v,k1:v1})

or

db.CollectionName.find({$or:[{k1:v1},{k2:v2}]})

and 和 or 聯(lián)合查詢

db.CollectionName.find({k:v,$or:[{k1:v1},{k2:v2}]})

排序查詢

db.CollectionName.find().sort({k:1})

指定返回行數(shù)查詢

db.CollectionName.find().limit()

db.CollectionName.find().skip()

指定返回域

db.CollectionName.find({k:v},{k1:1,k2:1})

只返回一條

db.CollectionName.findOne({k:v})

只返回一條并且刪除該數(shù)據(jù)

db.CollectionName.findOneAndDelete({k:v})

3.2 例子

數(shù)據(jù)準(zhǔn)備

> use LearnDB switched to db LearnDB > > db.dropDatabase() { "dropped" : "LearnDB", "ok" : 1 } > > > db.stu_info.insertMany([ ... {"name": "小明" , "sex": "男" , "score1": 98 , "score2": 60, "score3": 79 , "score5": 101 , "classID: " : 1}, ... {"name": "小紅" , "sex": "女" , "score1": 100 , "score2": 100, "score3": 100 , "score5": 80 , "classID: " : 3}, ... {"name": "小趙" , "sex": "女" , "score1": 80 , "score2": 79, "score3": 33 , "score5": 55 , "classID: " : 3}, ... {"name": "小錢" , "sex": "男" , "score1": 89 , "score2": 36, "score3": 102 , "score5": 65 , "classID: " : 5}, ... {"name": "小李" , "sex": "女" , "score1": 53 , "score2": 91, "score3": 34 , "score5": 19 , "classID: " : 9}, ... {"name": "小王" , "sex": "女" , "score1": 100 , "score2": 100, "score3": 100 , "score5": 99 , "classID: " : 1}, ... {"name": "小周" , "sex": "女" , "score1": 99 , "score2": 94, "score3": 92 , "score5": 90 , "classID: " : 6} ... ]) { "acknowledged" : true, "insertedIds" : [ ObjectId("61d6cac2a5a7b57ea8e0aa08"), ObjectId("61d6cac2a5a7b57ea8e0aa09"), ObjectId("61d6cac2a5a7b57ea8e0aa0a"), ObjectId("61d6cac2a5a7b57ea8e0aa0b"), ObjectId("61d6cac2a5a7b57ea8e0aa0c"), ObjectId("61d6cac2a5a7b57ea8e0aa0d"), ObjectId("61d6cac2a5a7b57ea8e0aa0e") ] } >

查詢集合文檔條數(shù)

> db.stu_info.count() 7 >

普通查詢

mongo shell 默認(rèn)只返回10條，超過10條 需要 根據(jù)提示往下翻頁

> db.stu_info.find() { "_id" : ObjectId("61d6cac2a5a7b57ea8e0aa08"), "name" : "小明", "sex" : "男", "score1" : 98, "score2" : 60, "score3" : 79, "score5" : 101, "classID: " : 1 } { "_id" : ObjectId("61d6cac2a5a7b57ea8e0aa09"), "name" : "小紅", "sex" : "女", "score1" : 100, "score2" : 100, "score3" : 100, "score5" : 80, "classID: " : 3 } { "_id" : ObjectId("61d6cac2a5a7b57ea8e0aa0a"), "name" : "小趙", "sex" : "女", "score1" : 80, "score2" : 79, "score3" : 33, "score5" : 55, "classID: " : 3 } { "_id" : ObjectId("61d6cac2a5a7b57ea8e0aa0b"), "name" : "小錢", "sex" : "男", "score1" : 89, "score2" : 36, "score3" : 102, "score5" : 65, "classID: " : 5 } { "_id" : ObjectId("61d6cac2a5a7b57ea8e0aa0c"), "name" : "小李", "sex" : "女", "score1" : 53, "score2" : 91, "score3" : 34, "score5" : 19, "classID: " : 9 } { "_id" : ObjectId("61d6cac2a5a7b57ea8e0aa0d"), "name" : "小王", "sex" : "女", "score1" : 100, "score2" : 100, "score3" : 100, "score5" : 99, "classID: " : 1 } { "_id" : ObjectId("61d6cac2a5a7b57ea8e0aa0e"), "name" : "小周", "sex" : "女", "score1" : 99, "score2" : 94, "score3" : 92, "score5" : 90, "classID: " : 6 } >

指定返回行數(shù)查詢

查詢2個(gè)文檔

> db.stu_info.find().limit(2) { "_id" : ObjectId("61d6cac2a5a7b57ea8e0aa08"), "name" : "小明", "sex" : "男", "score1" : 98, "score2" : 60, "score3" : 79, "score5" : 101, "classID: " : 1 } { "_id" : ObjectId("61d6cac2a5a7b57ea8e0aa09"), "name" : "小紅", "sex" : "女", "score1" : 100, "score2" : 100, "score3" : 100, "score5" : 80, "classID: " : 3 } >

跳過第1個(gè)文檔，查詢1個(gè)文檔

> db.stu_info.find().skip(1).limit(1) { "_id" : ObjectId("61d6cac2a5a7b57ea8e0aa09"), "name" : "小紅", "sex" : "女", "score1" : 100, "score2" : 100, "score3" : 100, "score5" : 80, "classID: " : 3 } >

格式化顯示

> db.stu_info.find().pretty().limit(2) { "_id" : ObjectId("61d6cac2a5a7b57ea8e0aa08"), "name" : "小明", "sex" : "男", "score1" : 98, "score2" : 60, "score3" : 79, "score5" : 101, "classID: " : 1 } { "_id" : ObjectId("61d6cac2a5a7b57ea8e0aa09"), "name" : "小紅", "sex" : "女", "score1" : 100, "score2" : 100, "score3" : 100, "score5" : 80, "classID: " : 3 } >

比較查詢

等于： 查詢 name 等于 小明 的文檔

> db.stu_info.find({"name":"小明"}) { "_id" : ObjectId("61d6cac2a5a7b57ea8e0aa08"), "name" : "小明", "sex" : "男", "score1" : 98, "score2" : 60, "score3" : 79, "score5" : 101, "classID: " : 1 } >

不等于： 查詢 name 不等于 小明 的文檔，并且取出第一個(gè)

> db.stu_info.find({"name":{$ne:"小明"}}).limit(1).pretty() { "_id" : ObjectId("61d6cac2a5a7b57ea8e0aa09"), "name" : "小紅", "sex" : "女", "score1" : 100, "score2" : 100, "score3" : 100, "score5" : 80, "classID: " : 3 } >

大于: 查詢 socre3 大于100 的文檔

> db.stu_info.find({"score3":{$gt:100}}) { "_id" : ObjectId("61d6cac2a5a7b57ea8e0aa0b"), "name" : "小錢", "sex" : "男", "score1" : 89, "score2" : 36, "score3" : 102, "score5" : 65, "classID: " : 5 } >

小于: 查詢 socre1 小于80 的文檔

> db.stu_info.find({"score1":{$lt:80}}) { "_id" : ObjectId("61d6cac2a5a7b57ea8e0aa0c"), "name" : "小李", "sex" : "女", "score1" : 53, "score2" : 91, "score3" : 34, "score5" : 19, "classID: " : 9 } >

大于或等于：查詢 socre3 大于等于 100 的文檔

> db.stu_info.find({"score3":{$gte:100}}) { "_id" : ObjectId("61d6cac2a5a7b57ea8e0aa09"), "name" : "小紅", "sex" : "女", "score1" : 100, "score2" : 100, "score3" : 100, "score5" : 80, "classID: " : 3 } { "_id" : ObjectId("61d6cac2a5a7b57ea8e0aa0b"), "name" : "小錢", "sex" : "男", "score1" : 89, "score2" : 36, "score3" : 102, "score5" : 65, "classID: " : 5 } { "_id" : ObjectId("61d6cac2a5a7b57ea8e0aa0d"), "name" : "小王", "sex" : "女", "score1" : 100, "score2" : 100, "score3" : 100, "score5" : 99, "classID: " : 1 } >

大于或等于：查詢 socre1 小于等于 80 的文檔

> db.stu_info.find({"score1":{$lte:80}}) { "_id" : ObjectId("61d6cac2a5a7b57ea8e0aa0a"), "name" : "小趙", "sex" : "女", "score1" : 80, "score2" : 79, "score3" : 33, "score5" : 55, "classID: " : 3 } { "_id" : ObjectId("61d6cac2a5a7b57ea8e0aa0c"), "name" : "小李", "sex" : "女", "score1" : 53, "score2" : 91, "score3" : 34, "score5" : 19, "classID: " : 9 } >

and | or 查詢

and：查詢 score1等于100 score2等于100 的文檔

> db.stu_info.find({"score1":100,"score2":100}) { "_id" : ObjectId("61d6cac2a5a7b57ea8e0aa09"), "name" : "小紅", "sex" : "女", "score1" : 100, "score2" : 100, "score3" : 100, "score5" : 80, "classID: " : 3 } { "_id" : ObjectId("61d6cac2a5a7b57ea8e0aa0d"), "name" : "小王", "sex" : "女", "score1" : 100, "score2" : 100, "score3" : 100, "score5" : 99, "classID: " : 1 } >

**or： 查詢socre1 等于 53 或者score2等于 94 的文檔 **

> db.stu_info.find({$or:[{"score1":53},{"score2":94}]}) { "_id" : ObjectId("61d6cac2a5a7b57ea8e0aa0c"), "name" : "小李", "sex" : "女", "score1" : 53, "score2" : 91, "score3" : 34, "score5" : 19, "classID: " : 9 } { "_id" : ObjectId("61d6cac2a5a7b57ea8e0aa0e"), "name" : "小周", "sex" : "女", "score1" : 99, "score2" : 94, "score3" : 92, "score5" : 90, "classID: " : 6 } >

and 和 or 聯(lián)合查詢 ：查詢sex 等于 男 ，在此基礎(chǔ)上 查詢 score1 等于 99 或者 score1 等于 91 的文檔

> db.stu_info.find({"sex":"女",$or:[{"score1":99},{"score2":91}]}) { "_id" : ObjectId("61d6cac2a5a7b57ea8e0aa0c"), "name" : "小李", "sex" : "女", "score1" : 53, "score2" : 91, "score3" : 34, "score5" : 19, "classID: " : 9 } { "_id" : ObjectId("61d6cac2a5a7b57ea8e0aa0e"), "name" : "小周", "sex" : "女", "score1" : 99, "score2" : 94, "score3" : 92, "score5" : 90, "classID: " : 6 } >

排序查詢： 對(duì)score1進(jìn)行升序和降序排序

1: 升序

-1: 降序

> db.stu_info.find().sort({"score1":1}) { "_id" : ObjectId("61d6cac2a5a7b57ea8e0aa0c"), "name" : "小李", "sex" : "女", "score1" : 53, "score2" : 91, "score3" : 34, "score5" : 19, "classID: " : 9 } { "_id" : ObjectId("61d6cac2a5a7b57ea8e0aa0a"), "name" : "小趙", "sex" : "女", "score1" : 80, "score2" : 79, "score3" : 33, "score5" : 55, "classID: " : 3 } { "_id" : ObjectId("61d6cac2a5a7b57ea8e0aa0b"), "name" : "小錢", "sex" : "男", "score1" : 89, "score2" : 36, "score3" : 102, "score5" : 65, "classID: " : 5 } { "_id" : ObjectId("61d6cac2a5a7b57ea8e0aa08"), "name" : "小明", "sex" : "男", "score1" : 98, "score2" : 60, "score3" : 79, "score5" : 101, "classID: " : 1 } { "_id" : ObjectId("61d6cac2a5a7b57ea8e0aa0e"), "name" : "小周", "sex" : "女", "score1" : 99, "score2" : 94, "score3" : 92, "score5" : 90, "classID: " : 6 } { "_id" : ObjectId("61d6cac2a5a7b57ea8e0aa09"), "name" : "小紅", "sex" : "女", "score1" : 100, "score2" : 100, "score3" : 100, "score5" : 80, "classID: " : 3 } { "_id" : ObjectId("61d6cac2a5a7b57ea8e0aa0d"), "name" : "小王", "sex" : "女", "score1" : 100, "score2" : 100, "score3" : 100, "score5" : 99, "classID: " : 1 } >

> db.stu_info.find().sort({"score1":-1}) { "_id" : ObjectId("61d6cac2a5a7b57ea8e0aa09"), "name" : "小紅", "sex" : "女", "score1" : 100, "score2" : 100, "score3" : 100, "score5" : 80, "classID: " : 3 } { "_id" : ObjectId("61d6cac2a5a7b57ea8e0aa0d"), "name" : "小王", "sex" : "女", "score1" : 100, "score2" : 100, "score3" : 100, "score5" : 99, "classID: " : 1 } { "_id" : ObjectId("61d6cac2a5a7b57ea8e0aa0e"), "name" : "小周", "sex" : "女", "score1" : 99, "score2" : 94, "score3" : 92, "score5" : 90, "classID: " : 6 } { "_id" : ObjectId("61d6cac2a5a7b57ea8e0aa08"), "name" : "小明", "sex" : "男", "score1" : 98, "score2" : 60, "score3" : 79, "score5" : 101, "classID: " : 1 } { "_id" : ObjectId("61d6cac2a5a7b57ea8e0aa0b"), "name" : "小錢", "sex" : "男", "score1" : 89, "score2" : 36, "score3" : 102, "score5" : 65, "classID: " : 5 } { "_id" : ObjectId("61d6cac2a5a7b57ea8e0aa0a"), "name" : "小趙", "sex" : "女", "score1" : 80, "score2" : 79, "score3" : 33, "score5" : 55, "classID: " : 3 } { "_id" : ObjectId("61d6cac2a5a7b57ea8e0aa0c"), "name" : "小李", "sex" : "女", "score1" : 53, "score2" : 91, "score3" : 34, "score5" : 19, "classID: " : 9 } >

指定返回域: 獲取name 和 score1 域的數(shù)據(jù)

> db.stu_info.find({},{"name":1,"score1":1}) { "_id" : ObjectId("61d6cac2a5a7b57ea8e0aa08"), "name" : "小明", "score1" : 98 } { "_id" : ObjectId("61d6cac2a5a7b57ea8e0aa09"), "name" : "小紅", "score1" : 100 } { "_id" : ObjectId("61d6cac2a5a7b57ea8e0aa0a"), "name" : "小趙", "score1" : 80 } { "_id" : ObjectId("61d6cac2a5a7b57ea8e0aa0b"), "name" : "小錢", "score1" : 89 } { "_id" : ObjectId("61d6cac2a5a7b57ea8e0aa0c"), "name" : "小李", "score1" : 53 } { "_id" : ObjectId("61d6cac2a5a7b57ea8e0aa0d"), "name" : "小王", "score1" : 100 } { "_id" : ObjectId("61d6cac2a5a7b57ea8e0aa0e"), "name" : "小周", "score1" : 99 } >

只返回一條：查詢socre1小于等于100的數(shù)據(jù)，僅返回一條

> db.stu_info.findOne({"score1": {$lte: 100}}) { "_id" : ObjectId("61d6cac2a5a7b57ea8e0aa08"), "name" : "小明", "sex" : "男", "score1" : 98, "score2" : 60, "score3" : 79, "score5" : 101, "classID: " : 1 } >

只返回一條并且刪除該數(shù)據(jù)：查詢socre1小于等于100的數(shù)據(jù)，僅返回一條，并且刪除

> db.stu_info.findOneAndDelete({"score1":{$lte:100}}) { "_id" : ObjectId("61d6cac2a5a7b57ea8e0aa08"), "name" : "小明", "sex" : "男", "score1" : 98, "score2" : 60, "score3" : 79, "score5" : 101, "classID: " : 1 } > db.stu_info.findOne({"name":"小明"}) null >

4. 更新操作

4.1 用法

更新一個(gè)文檔

db.CollectionName.updateOne()

更新多個(gè)文檔

db.CollectionName.updateOne()

db.CollectionName.updateMany()

4.2 例子

只更新一個(gè)文檔：將 score1 為 100 的文檔 新增一個(gè)classID 為 16

> db.stu_info.find({"score1":100}) { "_id" : ObjectId("61d6cac2a5a7b57ea8e0aa09"), "name" : "小紅", "sex" : "女", "score1" : 100, "score2" : 100, "score3" : 100, "score5" : 80, "classID: " : 3 } { "_id" : ObjectId("61d6cac2a5a7b57ea8e0aa0d"), "name" : "小王", "sex" : "女", "score1" : 100, "score2" : 100, "score3" : 100, "score5" : 99, "classID: " : 1 } > > db.stu_info.updateOne({"score1":100},{$set:{"classID":16}}) { "acknowledged" : true, "matchedCount" : 1, "modifiedCount" : 1 } > > db.stu_info.find({"score1":100}) { "_id" : ObjectId("61d6cac2a5a7b57ea8e0aa09"), "name" : "小紅", "sex" : "女", "score1" : 100, "score2" : 100, "score3" : 100, "score5" : 80, "classID: " : 3, "classID" : 16 } { "_id" : ObjectId("61d6cac2a5a7b57ea8e0aa0d"), "name" : "小王", "sex" : "女", "score1" : 100, "score2" : 100, "score3" : 100, "score5" : 99, "classID: " : 1 } >

更新多個(gè)文檔

更新所有文檔：將 score1 為 100 的文檔 設(shè)置 新增/設(shè)置一個(gè) classID 為 21

> db.stu_info.find({"score1":100}) { "_id" : ObjectId("61d6cac2a5a7b57ea8e0aa09"), "name" : "小紅", "sex" : "女", "score1" : 100, "score2" : 100, "score3" : 100, "score5" : 80, "classID: " : 3, "classID" : 16 } { "_id" : ObjectId("61d6cac2a5a7b57ea8e0aa0d"), "name" : "小王", "sex" : "女", "score1" : 100, "score2" : 100, "score3" : 100, "score5" : 99, "classID: " : 1 } > > db.stu_info.updateMany({"score1":100},{$set:{"classID":21}}) { "acknowledged" : true, "matchedCount" : 2, "modifiedCount" : 2 } > > db.stu_info.find({"score1":100}) { "_id" : ObjectId("61d6cac2a5a7b57ea8e0aa09"), "name" : "小紅", "sex" : "女", "score1" : 100, "score2" : 100, "score3" : 100, "score5" : 80, "classID: " : 3, "classID" : 21 } { "_id" : ObjectId("61d6cac2a5a7b57ea8e0aa0d"), "name" : "小王", "sex" : "女", "score1" : 100, "score2" : 100, "score3" : 100, "score5" : 99, "classID: " : 1, "classID" : 21 } >

5. 刪除操作

5.1 用法

刪除一條文檔

db.CollectionName.deleteOne()

刪除多條文檔

db.CollectionName.deleteMany()

5.2 例子

刪除一條文檔：刪除socre1為100的一條文檔

> db.stu_info.find({"score1":100}) { "_id" : ObjectId("61d6cac2a5a7b57ea8e0aa09"), "name" : "小紅", "sex" : "女", "score1" : 100, "score2" : 100, "score3" : 100, "score5" : 80, "classID: " : 3, "classID" : 21 } { "_id" : ObjectId("61d6cac2a5a7b57ea8e0aa0d"), "name" : "小王", "sex" : "女", "score1" : 100, "score2" : 100, "score3" : 100, "score5" : 99, "classID: " : 1, "classID" : 21 } > > db.stu_info.deleteOne({"score1":100}) { "acknowledged" : true, "deletedCount" : 1 } > > db.stu_info.find({"score1":100}) { "_id" : ObjectId("61d6cac2a5a7b57ea8e0aa0d"), "name" : "小王", "sex" : "女", "score1" : 100, "score2" : 100, "score3" : 100, "score5" : 99, "classID: " : 1, "classID" : 21 } >

刪除多條文檔: 刪除socre1小于90的所有文檔

> db.stu_info.find({"score1":{$lt:90}}) { "_id" : ObjectId("61d6cac2a5a7b57ea8e0aa0a"), "name" : "小趙", "sex" : "女", "score1" : 80, "score2" : 79, "score3" : 33, "score5" : 55, "classID: " : 3 } { "_id" : ObjectId("61d6cac2a5a7b57ea8e0aa0b"), "name" : "小錢", "sex" : "男", "score1" : 89, "score2" : 36, "score3" : 102, "score5" : 65, "classID: " : 5 } { "_id" : ObjectId("61d6cac2a5a7b57ea8e0aa0c"), "name" : "小李", "sex" : "女", "score1" : 53, "score2" : 91, "score3" : 34, "score5" : 19, "classID: " : 9 } > > db.stu_info.deleteMany({"score1":{$lt:90}}); { "acknowledged" : true, "deletedCount" : 3 } > > db.stu_info.find({"score1":{$lt:90}}) >

6. 索引操作

6.1 用法

查詢集合所有

db.CollectionName.getIndexes()

創(chuàng)建索引

db.CollectionName.createIndex()

刪除集合除_id以外的所有索引

db.CollectionName.dropIndexes()

刪除索引

db.CollectionName.dropIndex()

6.2 例子

查詢集合所有

> db.stu_info.getIndexes() [ { "v" : 2, "key" : { "_id" : 1 }, "name" : "_id_", "ns" : "LearnDB.stu_info" } ] >

創(chuàng)建索引

語法

db.collection.createIndex( { "a": 1 }, { unique: true, sparse: true, expireAfterSeconds: 3600 } )

可選參數(shù)

background: bool類型 為true則在后臺(tái)構(gòu)建索引，默認(rèn)為false unique: bool類型 為true則創(chuàng)建唯一索引，默認(rèn)為false name: string類型 索引名稱, 如果未指定，mongodb將通過索引字段和排序來生成索引名稱 sparse: bool類型 為true則對(duì)文檔不存在字段數(shù)據(jù)不啟用索引，默認(rèn)為false expireAfterSeconds: 整形 指定一個(gè)值(以秒為單位)作為TTL，設(shè)置生存時(shí)間

例子1： 給集合stu_info sex name 增加唯一索引

> db.stu_info.getIndexes() [ { "v" : 2, "key" : { "_id" : 1 }, "name" : "_id_", "ns" : "LearnDB.stu_info" } ] > > db.stu_info.createIndex({"name":1} , {"background":true,"unique":true , "name":"stu_info_name"}) { "createdCollectionAutomatically" : false, "numIndexesBefore" : 1, "numIndexesAfter" : 2, "ok" : 1 } > > db.stu_info.getIndexes() [ { "v" : 2, "key" : { "_id" : 1 }, "name" : "_id_", "ns" : "LearnDB.stu_info" }, { "v" : 2, "unique" : true, "key" : { "name" : 1 }, "name" : "stu_info_name", "ns" : "LearnDB.stu_info", "background" : true } ] >

嘗試新增相同name的文檔

> db.stu_info.find() { "_id" : ObjectId("61d6cac2a5a7b57ea8e0aa0d"), "name" : "小王", "sex" : "女", "score1" : 100, "score2" : 100, "score3" : 100, "score5" : 99, "classID: " : 1, "classID" : 21 } { "_id" : ObjectId("61d6cac2a5a7b57ea8e0aa0e"), "name" : "小周", "sex" : "女", "score1" : 99, "score2" : 94, "score3" : 92, "score5" : 90, "classID: " : 6 } > > db.stu_info.insertMany([ {"name": "小王" , "sex": "女" , "score1": 100 , "score2": 100, "score3": 100 , "score5": 99 , "classID: " : 1} ]) 2022-01-08T10:56:46.475+0800 E QUERY [js] BulkWriteError: write error at item 0 in bulk operation : BulkWriteError({ "writeErrors" : [ { "index" : 0, "code" : 11000, "errmsg" : "E11000 duplicate key error collection: LearnDB.stu_info index: stu_info_name dup key: { : \"小王\" }", "op" : { "_id" : ObjectId("61d8fd6e3a0069c72ccea003"), "name" : "小王", "sex" : "女", "score1" : 100, "score2" : 100, "score3" : 100, "score5" : 99, "classID: " : 1 } } ], "writeConcernErrors" : [ ], "nInserted" : 0, "nUpserted" : 0, "nMatched" : 0, "nModified" : 0, "nRemoved" : 0, "upserted" : [ ] }) BulkWriteError@src/mongo/shell/bulk_api.js:369:48 BulkWriteResult/this.toError@src/mongo/shell/bulk_api.js:333:24 Bulk/this.execute@src/mongo/shell/bulk_api.js:1173:1 DBCollection.prototype.insertMany@src/mongo/shell/crud_api.js:314:5 @(shell):1:1 >

刪除索引：刪除stu_info name 索引

> db.stu_info.getIndexes() [ { "v" : 2, "key" : { "_id" : 1 }, "name" : "_id_", "ns" : "LearnDB.stu_info" }, { "v" : 2, "unique" : true, "key" : { "name" : 1 }, "name" : "stu_info_name", "ns" : "LearnDB.stu_info", "background" : true } ] > > db.stu_info.dropIndex("stu_info_name") { "nIndexesWas" : 2, "ok" : 1 } > > db.stu_info.getIndexes() [ { "v" : 2, "key" : { "_id" : 1 }, "name" : "_id_", "ns" : "LearnDB.stu_info" } ] >

完

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