在 Linux 上配置 mongodb

ongoDB 是一個(gè)介于關(guān)系數(shù)據(jù)庫(kù)和非關(guān)系數(shù)據(jù)庫(kù)之間的產(chǎn)品，是非關(guān)系數(shù)據(jù)庫(kù)當(dāng)中功能最豐富，最像關(guān)系數(shù)據(jù)庫(kù)的。他支持的數(shù)據(jù)結(jié)構(gòu)非常松散，是類似json的bson格式，因此可以存儲(chǔ)比較復(fù)雜的數(shù)據(jù)類型。Mongo最大的特點(diǎn)是他支持的查詢語(yǔ)言非常強(qiáng)大，其語(yǔ)法有點(diǎn)類似于面向?qū)ο蟮牟樵冋Z(yǔ)言，幾乎可以實(shí)現(xiàn)類似關(guān)系數(shù)據(jù)庫(kù)單表查詢的絕大部分功能，而且還支持對(duì)數(shù)據(jù)建立索引。

1.下載Linux安裝包

如下圖，放到本地的某個(gè)角落，要記得位置哦~

2.連接你的服務(wù)器

ssh root@你的IP //回車輸入密碼

3.安裝包上傳

另開ssh窗口(command+n)，如果是windows就打開新的cmd窗口，因?yàn)槲覀円僮鞅镜匚募暗拇翱谖覀円呀?jīng)登了服務(wù)器了。傳的方法很多，我只演示其中一種。
cd "安裝包所在文件夾" // 去你剛才安裝包放的位置
scp "本地文件" root@你的IP // 回車輸入密碼開始傳送
如下圖，我是傳送到服務(wù)器的根目錄下。其實(shí)不建議，你可以放在一個(gè)固有目錄，比如/usr/local

ls -l //以列表的形式展開，我們可以看到已經(jīng)下載成功了。

4.解壓安裝包

tar -zxvf mongodb-linux-x86_64-3.4.6.tgz //解壓不同文件有不同的解壓命令，自己百度即可

5.填坑的一步

剛才說(shuō)大家可以把每次安裝的東東放到固定的文件夾，所以我把解壓好的文件移到了 /usr/local/mongodb目錄了，如果你已經(jīng)放到了你喜歡的位置，可以跳過(guò)此步驟。如果你不知道怎么移，可以看下。
cd /user/local //進(jìn)入local
mkdir mongodb //創(chuàng)建mongodb文件夾
cd / //進(jìn)入根目錄
mv mongodb-linux-x86_64-3.4.6 /usr/local/mongodb /*將剛才的解壓包移入 /usr/local/mongodb*/

6.配置mongodb運(yùn)行環(huán)境

mkdir data //創(chuàng)建data文件夾,存放數(shù)據(jù)庫(kù)db文件  
mkdir logs //創(chuàng)建logs文件夾,存放日志文件  
cd logs //進(jìn)入logs  
touch mongo.log //創(chuàng)建log文件  
cd .. //返回上一級(jí)  
mkdir etc //創(chuàng)建配置文件夾  
cd etc // 進(jìn)入etc  
vim mongo.conf //編輯同時(shí)創(chuàng)建mongo.conf 文件

以下是mongo.conf文件里的代碼，大家看好不要寫錯(cuò)，進(jìn)入文件之后要按一下鍵盤i才能開始編寫代碼。

dbpath = /usr/local/mongodb/data //路徑一定要輸入絕對(duì)的  
logpath = /usr/local/mongodb/logs/mongo.log //路徑一定要輸入絕對(duì)的  
logappend = true  
journal = true  
quiet = true  
port = 27017 //端口

寫好了按esc鍵退出，然后按shift+:會(huì)在最下面出現(xiàn):然后輸入wq，保存并退出的意思。

到了這一步就接近尾聲了。

7.啟動(dòng)mongodb

cd mongodb/mongodb-linux-x86_64-3.4.6/bin //進(jìn)入安裝包的bin目錄下 
mongod -f /usr/local/mongodb/etc/mongo.conf  //啟動(dòng)1方法  或 ./mongod -f /usr/local/mongodb/etc/mongo.conf  //啟動(dòng)2方法

如果輸入這個(gè)命令，出現(xiàn)如下圖，沒什么變化，只有光標(biāo)閃爍。

8.本地測(cè)試是否成功

我用的可視化工具 Robo 3t，新建鏈接，address輸入服務(wù)器地址，端口填你mongo.conf里配置的，基本都是27027。

點(diǎn)擊保存，如下圖操作，進(jìn)行 Connect。

如果到了這一步基本就是成功啦。

9.小坑警示

我之前在mongo.conf 里路徑寫的是相對(duì)的，就出現(xiàn)了下面的問(wèn)題。

然后就是這樣子的。

10.總結(jié)

方法有很多，我寫的只是其中一種，自己也是第一次安裝。其中也有點(diǎn)坑坑，遇到問(wèn)題不要認(rèn)輸，總會(huì)解決的，寫的不對(duì)不好的地方，希望大家不吝賜教~

本文地址：https://www.linuxprobe.com/linux-mongodb.html

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概述

MongoDB是一個(gè)可擴(kuò)展，高性能，開源，面向文檔的，基于鍵/值類型的數(shù)據(jù)庫(kù)。非常適合保存大對(duì)象及json格式的數(shù)據(jù)。本文將介紹MongoDB的單機(jī)和集群副本安裝，記錄下來(lái)以備后用。希望對(duì)有需要的朋友有所幫助和參考。

下載地址

# 歷史產(chǎn)品和版本選擇
https://www.mongodb.com/docs/legacy/

# 3.6版本文檔地址
https://www.mongodb.com/docs/v3.6/

安裝方式

StandAlone：?jiǎn)螜C(jī)環(huán)境，一般開發(fā)測(cè)試的時(shí)候用。
Replication：主從結(jié)構(gòu)，一個(gè)Primary，多個(gè)Secondary，可能會(huì)有Arbitry。

- Primary掛掉之后，會(huì)選舉出一個(gè)Secondary作為Primary，與zookeeper類似。
- Arbitry(仲裁節(jié)點(diǎn))上面不存數(shù)據(jù)，只是為了湊數(shù)。選舉算法要求節(jié)點(diǎn)數(shù)必須是奇數(shù)個(gè)，如果Primary+Secondary不是奇數(shù)個(gè)，就要用Arbitry湊數(shù)。
- 寫數(shù)據(jù)只能在Primary，讀數(shù)據(jù)默認(rèn)也在Primary，可以配置成從Secondary讀，可以選最近的節(jié)點(diǎn)。
- 數(shù)據(jù)在Primary上寫成功之后，會(huì)將操作記錄在oplog中，Secondary將oplog拷貝過(guò)去，然后照著操作一遍，就有數(shù)據(jù)了。
- Primary和Secondary上面的數(shù)據(jù)保證最終一致性，可以為寫操作配置write concern，有幾個(gè)級(jí)別：在Primary上寫完就認(rèn)為寫成功；寫到oplog后認(rèn)為寫成功；寫到一個(gè)/多個(gè)/某個(gè)/某幾個(gè)Secondary之后認(rèn)為寫成功，等等。

Sharding：share nothing的結(jié)構(gòu)，每臺(tái)機(jī)器只存一部分?jǐn)?shù)據(jù)。mongod服務(wù)器存數(shù)據(jù)，mongos服務(wù)器負(fù)責(zé)路由讀寫請(qǐng)求，元數(shù)據(jù)存在config數(shù)據(jù)庫(kù)中。

安裝&準(zhǔn)備

centos 系統(tǒng) yum源創(chuàng)建

cat >/etc/yum.repos.d/mongodb-org-3.6.repo<<eof
[mongodb-org-3.6]
name=MongoDB Repository
baseurl=https://repo.mongodb.org/yum/redhat/6Server/mongodb-org/3.6/x86_64/
gpgcheck=1
enabled=1
gpgkey=https://www.mongodb.org/static/pgp/server-3.6.asc
eof

根據(jù)具體情況，選擇版本安裝

# 安裝最近版本
# sudo yum install -y mongodb-org

# 安裝指定版本
sudo yum install --disablerepo=kubernetes -y mongodb-org-3.6.8 mongodb-org-server-3.6.8 mongodb-org-shell-3.6.8 mongodb-org-mongos-3.6.8 mongodb-org-tools-3.6.8

StandAlone安裝配置

默認(rèn)配置文件/etc/mongod.conf

- storage.dbPath 數(shù)據(jù)存儲(chǔ)目錄
- systemLog.path 系統(tǒng)日志目錄
- net.bindIp 訪問(wèn)ip綁定，默認(rèn)127.0.0.1。需要外部機(jī)器連接時(shí)，需調(diào)整成新人的訪問(wèn)源ip，或者測(cè)試所有ip放開0.0.0.0

啟動(dòng)MongoDB

sudo systemctl start mongod
# 如果啟動(dòng)報(bào)如下報(bào)錯(cuò)
# Failed to start mongod.service: Unit mongod.service not found.
# 啟動(dòng)以下命令
# sudo systemctl daemon-reload

查看MongoDB狀態(tài)

sudo systemctl status mongod
# 如果想要重啟系統(tǒng)MongoDB服務(wù)自動(dòng)啟動(dòng)，可設(shè)置以下命令
# sudo systemctl enable mongod

停止MongoDB

sudo systemctl stop mongod

重啟MongoDB

sudo systemctl restart mongod

連接MongoDB

mongo --host 127.0.0.1:27017

Replication安裝

參考文檔

官方文檔：https://www.mongodb.com/docs/v3.6/administration/replica-set-deployment/

環(huán)境

3個(gè)節(jié)點(diǎn)分別安裝MongoDB實(shí)例

修改/etc/mongod.conf以下配置項(xiàng)：

#replica set的名字
replication:
   replSetName: "rs0"
   
#client訪問(wèn)ip綁定，開發(fā)測(cè)試0.0.0.0所有ip   
net:
   bindIp: localhost,<ip address>

分別在3個(gè)節(jié)點(diǎn)上啟動(dòng)MongoDB服務(wù)

sudo systemctl start mongod
# 如果啟動(dòng)報(bào)如下報(bào)錯(cuò)
# Failed to start mongod.service: Unit mongod.service not found.
# 啟動(dòng)以下命令
# sudo systemctl daemon-reload

Initiate the replica set（初始化副本集）

任意一個(gè)節(jié)點(diǎn)控制臺(tái)登錄MongoDB

[root@dev2 ~]# mongo
MongoDB shell version v3.6.8
connecting to: mongodb://127.0.0.1:27017
MongoDB server version: 3.6.8
Server has startup warnings:
2022-05-11T09:36:02.035+0800 I CONTROL  [initandlisten]
2022-05-11T09:36:02.035+0800 I CONTROL  [initandlisten] ** WARNING: Access control is not enabled for the database.
2022-05-11T09:36:02.035+0800 I CONTROL  [initandlisten] **          Read and write access to data and configuration is unrestricted.
2022-05-11T09:36:02.035+0800 I CONTROL  [initandlisten]
2022-05-11T09:36:02.035+0800 I CONTROL  [initandlisten]
2022-05-11T09:36:02.035+0800 I CONTROL  [initandlisten] ** WARNING: /sys/kernel/mm/transparent_hugepage/enabled is 'always'.
2022-05-11T09:36:02.035+0800 I CONTROL  [initandlisten] **        We suggest setting it to 'never'
2022-05-11T09:36:02.035+0800 I CONTROL  [initandlisten]
2022-05-11T09:36:02.035+0800 I CONTROL  [initandlisten] ** WARNING: /sys/kernel/mm/transparent_hugepage/defrag is 'always'.
2022-05-11T09:36:02.035+0800 I CONTROL  [initandlisten] **        We suggest setting it to 'never'
2022-05-11T09:36:02.035+0800 I CONTROL  [initandlisten]
2022-05-11T09:36:02.035+0800 I CONTROL  [initandlisten] ** WARNING: soft rlimits too low. rlimits set to 4096 processes, 64000 files. Number of processes should be at least 32000 : 0.5 times number of files.
2022-05-11T09:36:02.035+0800 I CONTROL  [initandlisten]
>

初始化副本集。注：只需在集群一臺(tái)機(jī)器上執(zhí)行初始化命令。

rs.initiate( {
   _id : "rs0",
   members: [
      { _id: 0, host: "dev2:27017" },
      { _id: 1, host: "dev3:27017" },
      { _id: 2, host: "dev4:27017" }
   ]
})

執(zhí)行結(jié)果如下：

> rs.initiate( {
...    _id : "rs0",
...    members: [
...       { _id: 0, host: "dev2:27017" },
...       { _id: 1, host: "dev3:27017" },
...       { _id: 2, host: "dev4:27017" }
...    ]
... })
{
        "ok" : 1,
        "operationTime" : Timestamp(1653010782, 1),
        "$clusterTime" : {
                "clusterTime" : Timestamp(1653010782, 1),
                "signature" : {
                        "hash" : BinData(0,"AAAAAAAAAAAAAAAAAAAAAAAAAAA="),
                        "keyId" : NumberLong(0)
                }
        }
}

查看配置結(jié)果：控制臺(tái)執(zhí)行以下指令

rs.conf()

附錄

家好，我是Edison。

最近工作中需要用到MongoDB的事務(wù)操作，因此參考了一些資料封裝了一個(gè)小的組件，提供基礎(chǔ)的CRUD Repository基類和 UnitOfWork工作單元模式。今天，就來(lái)簡(jiǎn)單介紹一下這個(gè)小組件。

關(guān)于MongoDB的事務(wù)

MongoDB在4.2版本開始全面支持了多文檔事務(wù)，至今已過(guò)了四年了，雖然我們可能沒有在項(xiàng)目中用MongoDB來(lái)替代傳統(tǒng)關(guān)系型數(shù)據(jù)庫(kù)如MySQL/SQL Server，但是不能否認(rèn)MongoDB已經(jīng)在事務(wù)能力上愈發(fā)成熟了。

在MongoDB中，所謂的事務(wù)主要指的是多個(gè)文檔的事務(wù)，其使用方式和傳統(tǒng)關(guān)系型數(shù)據(jù)庫(kù)差不多。但我們需要注意的是：多文檔事務(wù)只能應(yīng)用在副本集或 mongos 節(jié)點(diǎn)上。如果你只是一個(gè)單點(diǎn)的mongo實(shí)例，是無(wú)法進(jìn)行多文檔事務(wù)實(shí)踐的。

畫外音：如果你對(duì)MongoDB感興趣，不妨看看我的這個(gè)系列博客：《MongoDB入門到實(shí)踐學(xué)習(xí)之旅》

那么，如何快速進(jìn)行事務(wù)操作呢？

在Mongo Shell中進(jìn)行事務(wù)

下面演示了如何通過(guò)Mongo Shell來(lái)進(jìn)行一個(gè)多文檔操作的事務(wù)提交：

var session = db.getMongo().startSession();session.startTransaction({readConcern: { level: 'majority' },writeConcern: { w: 'majority' }});
var coll1 = session.getDatabase('students').getCollection('teams');coll1.update({name: 'yzw-football-team'}, {$set: {members: 20}});
var coll2 = session.getDatabase('students').getCollection('records');coll1.update({name: 'Edison'}, {$set: {gender: 'Female'}});
// 成功提交事務(wù)session.commitTransaction();
// 失敗事務(wù)回滾session.abortTransaction();

在.NET應(yīng)用中進(jìn)行事務(wù)

下面展示了在.NET應(yīng)用中通過(guò)MongoDB Driver來(lái)進(jìn)行事務(wù)的示例：

using (var clientSession = mongoClient.StartSession()){ try { var contacts = clientSession.Client.GetDatabase("testDB").GetCollection<Contact>("contacts"); contacts.ReplaceOne(contact => contact.Id == "1234455", contact); var books = clientSession.Client.GetDatabase("testDB").GetCollection<Book>("books"); books.DeleteOne(book => book.Id == "1234455");
 clientSession.CommitTransaction(); } catch (Exception ex) { // to do some logging clientSession.AbortTransaction(); }}

在大部分的實(shí)際應(yīng)用中，我們通常都習(xí)慣使用數(shù)據(jù)倉(cāng)儲(chǔ)（Repository）的模式來(lái)進(jìn)行CRUD，同時(shí)也習(xí)慣用工作單元（UnitOfWork）模式來(lái)進(jìn)行協(xié)調(diào)多個(gè)Repository進(jìn)行事務(wù)提交。

那么，如何在自己的項(xiàng)目中實(shí)現(xiàn)這個(gè)呢？

參考了一些資料后，自己實(shí)現(xiàn)了一個(gè)基礎(chǔ)小組件，暫且叫它：EDT.MongoProxy吧，我們來(lái)看看它是如何實(shí)現(xiàn)的。

單例的MongoClient

基于MongoDB的最佳時(shí)間，對(duì)于MongoClient最好設(shè)置為單例注入，這樣可以避免反復(fù)實(shí)例化MongoClient帶來(lái)的開銷，避免在極端情況下的性能低下。

這里暫且設(shè)計(jì)一個(gè)MongoDbConnection類，用于包裹這個(gè)MongoClient，然后將其以單例模式注入IoC容器中。

public class MongoDbConnection : IMongoDbConnection{ public IMongoClient DatabaseClient { get; } public string DatabaseName { get; }
 public MongoDbConnection(MongoDatabaseConfigs configs, IConfiguration configuration) { DatabaseClient = new MongoClient(configs.GetMongoClientSettings(configuration)); DatabaseName = configs.DatabaseName; }}

其中，這個(gè)MongoDatabaseConfigs類主要是獲取appsettings中的配置，用以生成MongoClient的對(duì)應(yīng)Settings。

/** Config Example"MongoDatabaseConfigs": { "Servers": "xxx01.edisontalk.net,xxx02.edisontalk.net,xxx03.edisontalk.net", "Port": 27017, "ReplicaSetName": "edt-replica", "DatabaseName": "EDT_Practices", "AuthDatabaseName": "admin",
 "ApplicationName": "Todo", "UserName": "service_testdev", "Password": "xxxxxxxxxxxxxxxxxxxxxxxx", "UseTLS": true, "AllowInsecureTLS": true, "SslCertificatePath": "/etc/pki/tls/certs/EDT_CA.cer", "UseEncryption": true}**/public class MongoDatabaseConfigs{ private const string DEFAULT_AUTH_DB = "admin"; // Default AuthDB: admin
 public string Servers { get; set; } public int Port { get; set; } = 27017; // Default Port: 27017 public string ReplicaSetName { get; set; } public string DatabaseName { get; set; } public string DefaultCollectionName { get; set; } = string.Empty; public string ApplicationName { get; set; } public string UserName { get; set; } public string Password { get; set; } public string AuthDatabaseName { get; set; } = DEFAULT_AUTH_DB; // Default AuthDB: admin public string CustomProperties { get; set; } = string.Empty; public bool UseTLS { get; set; } = false; public bool AllowInsecureTLS { get; set; } = true; public string SslCertificatePath { get; set; } = string.Empty; public bool StoreCertificateInKeyStore { get; set; } = false;

 public MongoClientSettings GetMongoClientSettings(IConfiguration configuration = ) { if (string.IsOrWhiteSpace(Servers)) throw new ArgumentException("Mongo Servers Configuration is Missing!");
 if (string.IsOrWhiteSpace(UserName) || string.IsOrWhiteSpace(Password)) throw new ArgumentException("Mongo Account Configuration is Missing!");
 // Base Configuration MongoClientSettings settings = new MongoClientSettings { ApplicationName = ApplicationName, ReplicaSetName = ReplicaSetName };

 // Credential settings.Credential = MongoCredential.CreateCredential(AuthDatabaseName, UserName, Password);
 // Servers var mongoServers = Servers.Split(",", StringSplitOptions.RemoveEmptyEntries).ToList(); if (mongoServers.Count == 1) // Standalone { settings.Server = new MongoServerAddress(mongoServers.First(), Port); settings.DirectConnection = true; }
 if (mongoServers.Count > 1) // Cluster { var mongoServerAddresses = new List<MongoServerAddress>(); foreach (var mongoServer in mongoServers) { var mongoServerAddress = new MongoServerAddress(mongoServer, Port); mongoServerAddresses.Add(mongoServerAddress); } settings.Servers = mongoServerAddresses; settings.DirectConnection = false; }
 // SSL if (UseTLS) { settings.UseTls = true; settings.AllowInsecureTls = AllowInsecureTLS; if (string.IsOrWhiteSpace(SslCertificatePath)) throw new ArgumentException("SslCertificatePath is Missing!");
 if (StoreCertificateInKeyStore) { var localTrustStore = new X509Store(StoreName.Root); var certificateCollection = new X509Certificate2Collection(); certificateCollection.Import(SslCertificatePath); try { localTrustStore.Open(OpenFlags.ReadWrite); localTrustStore.AddRange(certificateCollection); } catch (Exception ex) { throw; } finally { localTrustStore.Close(); } }
 var certs = new List<X509Certificate> { new X509Certificate2(SslCertificatePath) }; settings.SslSettings = new SslSettings(); settings.SslSettings.ClientCertificates = certs; settings.SslSettings.EnabledSslProtocols = System.Security.Authentication.SslProtocols.Tls13; }
 return settings; }}

核心部分：MongoDbContext

這里我們主要仿照DbContext的設(shè)計(jì)，設(shè)計(jì)一個(gè)MongoDbContext，它從IoC容器中獲取到單例的MongoClient，封裝了事務(wù)的開啟和提交，簡(jiǎn)化了應(yīng)用代碼的編寫。

public class MongoDbContext : IMongoDbContext{ private readonly IMongoDatabase _database; private readonly IMongoClient _mongoClient; private readonly IList<Func<IClientSessionHandle, Task>> _commands = new List<Func<IClientSessionHandle, Task>>();
 public MongoDbContext(IMongoDbConnection dbClient) { _mongoClient = dbClient.DatabaseClient; _database = _mongoClient.GetDatabase(dbClient.DatabaseName); }
 public void AddCommand(Func<IClientSessionHandle, Task> func) { _commands.Add(func); }
 public async Task AddCommandAsync(Func<IClientSessionHandle, Task> func) { _commands.Add(func); await Task.CompletedTask; }
 /// <summary> /// NOTES: Only works in Cluster mode /// </summary> public int Commit(IClientSessionHandle session) { try { session.StartTransaction();
 foreach (var command in _commands) { command(session); }
 session.CommitTransaction(); return _commands.Count; } catch (Exception ex) { session.AbortTransaction(); return 0; } finally { _commands.Clear(); } }
 /// <summary> /// NOTES: Only works in Cluster mode /// </summary> public async Task<int> CommitAsync(IClientSessionHandle session) { try { session.StartTransaction();
 foreach (var command in _commands) { await command(session); }
 await session.CommitTransactionAsync(); return _commands.Count; } catch (Exception ex) { await session.AbortTransactionAsync(); return 0; } finally { _commands.Clear(); } }
 public IClientSessionHandle StartSession() { var session = _mongoClient.StartSession(); return session; }
 public async Task<IClientSessionHandle> StartSessionAsync() { var session = await _mongoClient.StartSessionAsync(); return session; }
 public IMongoCollection<T> GetCollection<T>(string name) { return _database.GetCollection<T>(name); }
 public void Dispose() { GC.SuppressFinalize(this); }}

數(shù)據(jù)倉(cāng)儲(chǔ)：MongoRepositoryBase

在實(shí)際項(xiàng)目中，我們都希望有一個(gè)基礎(chǔ)的RepositoryBase類，將CRUD的方法都封裝了，我們實(shí)際中就只需要?jiǎng)?chuàng)建一個(gè)對(duì)應(yīng)的Repository集成這個(gè)RepositoryBase就行了，無(wú)需再重復(fù)編寫CRUD的方法。那么，也就有了這個(gè)MongoRepositoryBase類：

public class MongoRepositoryBase<TEntity> : IMongoRepositoryBase<TEntity> where TEntity : MongoEntityBase, new(){ protected readonly IMongoDbContext _dbContext; protected readonly IMongoCollection<TEntity> _dbSet; private readonly string _collectionName; private const string _keyField = "_id";
 public MongoRepositoryBase(IMongoDbContext mongoDbContext) { _dbContext = mongoDbContext; _collectionName = typeof(TEntity).GetAttributeValue((TableAttribute m) => m.Name) ?? typeof(TEntity).Name; if (string.IsOrWhiteSpace(_collectionName)) throw new ArgumentException("Mongo DatabaseName can't be ! Please set the attribute Table in your entity class.");
 _dbSet = mongoDbContext.GetCollection<TEntity>(_collectionName); }
 #region Create Part
 public async Task AddAsync(TEntity entity, IClientSessionHandle session = ) { if (session == ) await _dbSet.InsertOneAsync(entity); else await _dbContext.AddCommandAsync(async (session) => await _dbSet.InsertOneAsync(entity)); }
 public async Task AddManyAsync(IEnumerable<TEntity> entityList, IClientSessionHandle session = ) { if (session == ) await _dbSet.InsertManyAsync(entityList); else await _dbContext.AddCommandAsync(async (session) => await _dbSet.InsertManyAsync(entityList)); }
 #endregion
 # region Delete Part
 public async Task DeleteAsync(string id, IClientSessionHandle session = ) { if (session == ) await _dbSet.DeleteOneAsync(Builders<TEntity>.Filter.Eq(_keyField, new ObjectId(id))); else await _dbContext.AddCommandAsync(async (session) => await _dbSet.DeleteOneAsync(Builders<TEntity>.Filter.Eq(_keyField, new ObjectId(id)))); }
 public async Task DeleteAsync(Expression<Func<TEntity, bool>> expression, IClientSessionHandle session = ) { if (session == ) await _dbSet.DeleteOneAsync(expression); else await _dbContext.AddCommandAsync(async (session) => await _dbSet.DeleteOneAsync(expression)); }
 public async Task<DeleteResult> DeleteManyAsync(FilterDefinition<TEntity> filter, IClientSessionHandle session = ) { if (session == ) return await _dbSet.DeleteManyAsync(filter);
 await _dbContext.AddCommandAsync(async (session) => await _dbSet.DeleteManyAsync(filter)); return new DeleteResult.Acknowledged(10); }
 public async Task<DeleteResult> DeleteManyAsync(Expression<Func<TEntity, bool>> expression, IClientSessionHandle session = ) { if (session == ) return await _dbSet.DeleteManyAsync(expression);
 await _dbContext.AddCommandAsync(async (session) => await _dbSet.DeleteManyAsync(expression)); return new DeleteResult.Acknowledged(10); }
 #endregion
 #region Update Part
 public async Task UpdateAsync(TEntity entity, IClientSessionHandle session = ) { if (session == ) await _dbSet.ReplaceOneAsync(item => item.Id == entity.Id, entity); else await _dbContext.AddCommandAsync(async (session) => await _dbSet.ReplaceOneAsync(item => item.Id == entity.Id, entity)); }
 public async Task UpdateAsync(Expression<Func<TEntity, bool>> expression, Expression<Action<TEntity>> entity, IClientSessionHandle session = ) { var fieldList = new List<UpdateDefinition<TEntity>>();
 if (entity.Body is MemberInitExpression param) { foreach (var item in param.Bindings) { var propertyName = item.Member.Name; object propertyValue = ;
 if (item is not MemberAssignment memberAssignment) continue;
 if (memberAssignment.Expression.NodeType == ExpressionType.Constant) { if (memberAssignment.Expression is ConstantExpression constantExpression) propertyValue = constantExpression.Value; } else { propertyValue = Expression.Lambda(memberAssignment.Expression, ).Compile().DynamicInvoke(); }
 if (propertyName != _keyField) { fieldList.Add(Builders<TEntity>.Update.Set(propertyName, propertyValue)); } } }
 if (session == ) await _dbSet.UpdateOneAsync(expression, Builders<TEntity>.Update.Combine(fieldList)); else await _dbContext.AddCommandAsync(async (session) => await _dbSet.UpdateOneAsync(expression, Builders<TEntity>.Update.Combine(fieldList))); }
 public async Task UpdateAsync(FilterDefinition<TEntity> filter, UpdateDefinition<TEntity> update, IClientSessionHandle session = ) { if (session == ) await _dbSet.UpdateOneAsync(filter, update); else await _dbContext.AddCommandAsync(async (session) => await _dbSet.UpdateOneAsync(filter, update)); }
 public async Task UpdateManyAsync(Expression<Func<TEntity, bool>> expression, UpdateDefinition<TEntity> update, IClientSessionHandle session = ) { if (session == ) await _dbSet.UpdateManyAsync(expression, update); else await _dbContext.AddCommandAsync(async (session) => await _dbSet.UpdateManyAsync(expression, update)); }
 public async Task<UpdateResult> UpdateManayAsync(Dictionary<string, string> dic, FilterDefinition<TEntity> filter, IClientSessionHandle session = ) { var t = new TEntity(); // Fields to be updated var list = new List<UpdateDefinition<TEntity>>(); foreach (var item in t.GetType().GetProperties()) { if (!dic.ContainsKey(item.Name)) continue; var value = dic[item.Name]; list.Add(Builders<TEntity>.Update.Set(item.Name, value)); } var updatefilter = Builders<TEntity>.Update.Combine(list);
 if (session == ) return await _dbSet.UpdateManyAsync(filter, updatefilter);
 await _dbContext.AddCommandAsync(async (session) => await _dbSet.UpdateManyAsync(filter, updatefilter)); return new UpdateResult.Acknowledged(10, 10, ); }
 #endregion
 #region Read Part
 public async Task<TEntity> GetAsync(Expression<Func<TEntity, bool>> expression, bool readFromPrimary = true) { var readPreference = GetReadPreference(readFromPrimary); var queryData = await _dbSet.WithReadPreference(readPreference) .Find(expression) .FirstOrDefaultAsync(); return queryData; }
 public async Task<TEntity> GetAsync(string id, bool readFromPrimary = true) { var readPreference = GetReadPreference(readFromPrimary); var queryData = await _dbSet.WithReadPreference(readPreference).FindAsync(Builders<TEntity>.Filter.Eq(_keyField, new ObjectId(id))); return queryData.FirstOrDefault(); }
 public async Task<IEnumerable<TEntity>> GetAllAsync(bool readFromPrimary = true) { var readPreference = GetReadPreference(readFromPrimary); var queryAllData = await _dbSet.WithReadPreference(readPreference).FindAsync(Builders<TEntity>.Filter.Empty); return queryAllData.ToList(); }
 public async Task<long> CountAsync(Expression<Func<TEntity, bool>> expression, bool readFromPrimary = true) { var readPreference = GetReadPreference(readFromPrimary); return await _dbSet.WithReadPreference(readPreference).CountDocumentsAsync(expression); }
 public async Task<long> CountAsync(FilterDefinition<TEntity> filter, bool readFromPrimary = true) { var readPreference = GetReadPreference(readFromPrimary); return await _dbSet.WithReadPreference(readPreference).CountDocumentsAsync(filter); }
 public async Task<bool> ExistsAsync(Expression<Func<TEntity, bool>> predicate, bool readFromPrimary = true) { var readPreference = GetReadPreference(readFromPrimary); return await Task.FromResult(_dbSet.WithReadPreference(readPreference).AsQueryable().Any(predicate)); }
 public async Task<List<TEntity>> FindListAsync(FilterDefinition<TEntity> filter, string[]? field = , SortDefinition<TEntity>? sort = , bool readFromPrimary = true) { var readPreference = GetReadPreference(readFromPrimary); if (field ==  || field.Length == 0) { if (sort == ) return await _dbSet.WithReadPreference(readPreference).Find(filter).ToListAsync();
 return await _dbSet.WithReadPreference(readPreference).Find(filter).Sort(sort).ToListAsync(); }
 var fieldList = new List<ProjectionDefinition<TEntity>>(); for (int i = 0; i < field.Length; i++) { fieldList.Add(Builders<TEntity>.Projection.Include(field[i].ToString())); } var projection = Builders<TEntity>.Projection.Combine(fieldList); fieldList?.Clear();
 if (sort == ) return await _dbSet.WithReadPreference(readPreference).Find(filter).Project<TEntity>(projection).ToListAsync();
 return await _dbSet.WithReadPreference(readPreference).Find(filter).Sort(sort).Project<TEntity>(projection).ToListAsync(); }
 public async Task<List<TEntity>> FindListByPageAsync(FilterDefinition<TEntity> filter, int pageIndex, int pageSize, string[]? field = , SortDefinition<TEntity>? sort = , bool readFromPrimary = true) { var readPreference = GetReadPreference(readFromPrimary); if (field ==  || field.Length == 0) { if (sort == ) return await _dbSet.WithReadPreference(readPreference).Find(filter).Skip((pageIndex - 1) * pageSize).Limit(pageSize).ToListAsync();
 return await _dbSet.WithReadPreference(readPreference).Find(filter).Sort(sort).Skip((pageIndex - 1) * pageSize).Limit(pageSize).ToListAsync(); }
 var fieldList = new List<ProjectionDefinition<TEntity>>(); for (int i = 0; i < field.Length; i++) { fieldList.Add(Builders<TEntity>.Projection.Include(field[i].ToString())); } var projection = Builders<TEntity>.Projection.Combine(fieldList); fieldList?.Clear();
 if (sort == ) return await _dbSet.WithReadPreference(readPreference).Find(filter).Project<TEntity>(projection).Skip((pageIndex - 1) * pageSize).Limit(pageSize).ToListAsync();
 return await _dbSet.WithReadPreference(readPreference).Find(filter).Sort(sort).Project<TEntity>(projection).Skip((pageIndex - 1) * pageSize).Limit(pageSize).ToListAsync(); }
 #endregion
 #region Protected Methods
 protected ReadPreference GetReadPreference(bool readFromPrimary) { if (readFromPrimary) return ReadPreference.PrimaryPreferred; else return ReadPreference.SecondaryPreferred; }
 #endregion}

工作單元：UnitOfWork

在實(shí)際項(xiàng)目中，在對(duì)多個(gè)Repository操作之后，我們希望有一個(gè)統(tǒng)一的提交操作來(lái)實(shí)現(xiàn)事務(wù)的原子性。因此，我們可以有一個(gè)UnitOfWork來(lái)作為代理：

public class UnitOfWork : IUnitOfWork{ private readonly IMongoDbContext _context;
 public UnitOfWork(IMongoDbContext context) { _context = context; }
 public bool SaveChanges(IClientSessionHandle session) { return _context.Commit(session) > 0; }
 public async Task<bool> SaveChangesAsync(IClientSessionHandle session) { return await _context.CommitAsync(session) > 0; }
 public IClientSessionHandle BeginTransaction() { return _context.StartSession(); }
 public async Task<IClientSessionHandle> BeginTransactionAsync() { return await _context.StartSessionAsync(); }
 public void Dispose() { _context.Dispose(); }}

封裝注入：ServiceCollectionExtensions

為了便于應(yīng)用中快速注入，我們可以簡(jiǎn)單封裝一個(gè)擴(kuò)展方法，快速注入相關(guān)的核心組成部分：

public static class ServiceCollectionExtensions{ /// <summary> /// MongoDB Config Injection /// </summary> public static IServiceCollection AddMongoProxy(this IServiceCollection services, IConfiguration configuration) { if (!configuration.GetSection(nameof(MongoDatabaseConfigs)).Exists()) return services;
 services.Configure<MongoDatabaseConfigs>(configuration.GetSection(nameof(MongoDatabaseConfigs))); services.AddSingleton(sp => sp.GetRequiredService<IOptions<MongoDatabaseConfigs>>().Value); services.AddSingleton<IMongoDbConnection, MongoDbConnection>(); services.AddScoped<IMongoDbContext, MongoDbContext>(); services.AddScoped<IUnitOfWork, UnitOfWork>();
 return services; }}

如何使用：三步上籃

第一步：注入MongoProxy核心部分

在appsettings中配置MongoDB的連接信息：

```
"MongoDatabaseConfigs": { "Servers": "xxx01.edisontalk.net,xxx02.edisontalk.net,xxx03.edisontalk.net", "Port": 27017, "ReplicaSetName": "edt-replica", "DatabaseName": "EDT_Practices", "UserName": "xxxxxxxxxxxxx", "Password": "xxxxxxxxxxxxx"}
```
然后通過(guò)擴(kuò)展方法注入MongoProxy相關(guān)部分：
```
builder.Services.AddMongoProxy(builder.Configuration);
```
第二步：添加Entity 和 Repository
示例Entity：
- ```
[Table("Orders")]public class OrderEntity : MongoEntityBase, IEntity{ public string OrderNumber { get; set; } public List<TransmissionEntity> Transmissions { get; set; }}
```
  示例Repository：
  - public interface ITodoItemRepository : IMongoRepositoryBase<TodoItem>{}public class TodoItemRepository : MongoRepositoryBase<TodoItem>, ITodoItemRepository{ public TodoItemRepository(IMongoDbContext mongoDbContext) : base(mongoDbContext) { }}services.AddScoped<ITodoItemRepository, TodoItemRepository>();services.AddScoped<IOrderRepository, OrderRepository>();
    第三步：使用Repository 和 UnitOfWork
    # 非事務(wù)模式await _taskRepository.AddManyAsync(newTasks);# 事務(wù)模式（借助UnitOfWork工作單元）private readonly IUnitOfWork _unitOfWork;public OrderService(IUnitOfWork unitOfWork, ......){ _unitOfWork = unitOfWork; ......}public async Task Example(){ using var session = await _unitOfWork.BeginTransactionAsync()) await _taskRepository.AddManyAsync(newTasks, session); await _orderRepository.AddAsync(newOrder, session); await _unitOfWork.SaveChangesAsync(session);}
    小結(jié)
    本文介紹了MongoDB事務(wù)的基本概念和如何通過(guò).NET操作事務(wù)，重點(diǎn)介紹了EDT.MongoProxy這個(gè)小組件的設(shè)計(jì)，讓我們可以在ASP.NET 6應(yīng)用中通過(guò)數(shù)據(jù)倉(cāng)儲(chǔ)（Repository）和工作單元（UnitOfWork）的模式來(lái)快速方便地操作MongoDB的事務(wù)。
    參考代碼
    本文代碼并未提供所有的，如需查看，請(qǐng)至下面的代碼倉(cāng)庫(kù)中查看，也可以點(diǎn)個(gè)贊給點(diǎn)鼓勵(lì)。
    GitHub：https://github.com/Coder-EdisonZhou/EDT.MongoProxy
    參考資料
    追逐時(shí)光者，《.NET Core MongoDB數(shù)據(jù)倉(cāng)儲(chǔ)和工作單元實(shí)操》：https://www.cnblogs.com/Can-daydayup/p/17157135.html
    *本文主要設(shè)計(jì)參考自這篇文章，值得一讀！
    TheCodeBuzz,《MongoDB Repository Implementation in .NET Core》：
    https://www.thecodebuzz.com/mongodb-repository-implementation-unit-testing-net-core-example
    Bryan Avery, 《ASP.NET Core - MongoDB Repository Pattern & Unit Of Work》:
    https://bryanavery.co.uk/asp-net-core-mongodb-repository-pattern-unit-of-work
    年終總結(jié)：Edison的2022年終總結(jié)
    數(shù)字化轉(zhuǎn)型：我在傳統(tǒng)企業(yè)做數(shù)字化轉(zhuǎn)型
    C#刷題：C#刷劍指Offer算法題系列文章目錄
    .NET面試：.NET開發(fā)面試知識(shí)體系
    .NET大會(huì)：2020年中國(guó).NET開發(fā)者大會(huì)PDF資料

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