C# 串接 MongoDB

前言

雖說之前有看過 Mongo University，也了解過一些 MongoDB 相關知識，但許久沒用都忘的差不多了，所以重新學習並記錄一下使用方式。

環境建置(使用 Docker)

Pull Image：
docker pull mongo

Run in Container：
docker run --name samplemongo -v ./data:/data/db -d -p 27017:27017 --rm mongo:latest

下載 GUI ( MongoDB Compass ) 並進行連線：

成功後，回到專案內下載 Nuget( MongoDB.Driver )：

使用方式

定義好要存的資料型態：

public class CourseModel
{
    [BsonId]
    public string CourseId { get; set;}

    [BsonElement]
    public string CourseName { get; set; }

    [BsonElement]
    public string Teacher { get; set; }

    [BsonElement]
    public List<Student> Students { get; set; }
}

public class Student
{
    public int Id { get; set; }

    public string Name { get; set; }
}

接著建立連線並寫入一筆資料：

static async Task Main(string[] args)
{
    // 連線字串
    string connectionString = "mongodb://localhost:27017";
    // 連接 MongoDB
    MongoClient client = new MongoClient(connectionString);
    // 取得 MongoDB 資料庫
    IMongoDatabase database = client.GetDatabase("Sample");
    // 取得 Collection(相當於 sql 的資料表)
    IMongoCollection<CourseModel> collection = database.GetCollection<CourseModel>("Course");
    
    CourseModel course = new CourseModel
    {
        CourseId = "AA123",
        CourseName = "英文",
        Teacher = "Amy",
        Students = new List<Student>
        {
            new Student { Id = 1314, Name = "Feii" },
            new Student { Id = 1315, Name = "Danny" }
        }
    };

    // 寫入至 MongoDB
    await collection.InsertOneAsync(course);
}

查看寫入資料：

Mongo CRUD

這邊我先建立一個類別存取配置檔

public class CourseMongoDatabaseSetting
{
    /// <summary>
    /// 連線字串
    /// </summary>
    public string ConnectionString { get; set; }
    /// <summary>
    /// 資料庫
    /// </summary>
    public string Database { get; set; }
    /// <summary>
    /// Collection
    /// </summary>
    public string Collection { get; set; }
}

接著建立 MongoRepository 建構子吃 CourseMongoDatabaseSetting 類別

public class MongoRepository
{
    private readonly IMongoCollection<CourseModel> _collection;

    public MongoRepository(CourseMongoDatabaseSetting setting)
    {
        MongoClient client = new MongoClient(setting.ConnectionString);

        IMongoDatabase database = client.GetDatabase(setting.Database);

        _collection = database.GetCollection<CourseModel>(setting.Collection);
    }

    /// <summary>
    /// 建立課程
    /// </summary>
    public async Task<bool> CreateCourse(CourseModel model)
    {
        await _collection.InsertOneAsync(model);
        return true;
    }

    /// <summary>
    /// 更新課程
    /// </summary>
    public async Task<bool> UpdateCourse(UpdateCourseModel model)
    {
        var update = new UpdateDefinitionBuilder<CourseModel>()
            .Set(x => x.Teacher, model.Teacher)
            .Set(x => x.CourseName, model.CourseName);

        await _collection.UpdateOneAsync(x => x.CourseId == model.CourseId, update);
        return true;
    }

    /// <summary>
    /// 取得一個課程
    /// </summary>
    public async Task<CourseModel> GetCourse(string courseId)
    {
        var result = await _collection.Find(x => x.CourseId == courseId).FirstOrDefaultAsync();
        return result;
    }

    /// <summary>
    /// 取得全部課程
    /// </summary>
    public async Task<List<CourseModel>> GetAllCourse()
    {
        var result = await _collection.Find(_ => true).ToListAsync();
        return result;
    }

    /// <summary>
    /// 刪除課程
    /// </summary>
    public async Task<bool> DeleteCourse(string courseId)
    {
        await _collection.DeleteOneAsync(x => x.CourseId == courseId);
        return true;
    }
}

接著就可以觀察結果，如下：

static async Task Main(string[] args)
{
    var setting = new CourseMongoDatabaseSetting
    {
        ConnectionString = "mongodb://localhost:27017",
        Database = "Sample",
        Collection = "Course"
    };

    // 建立 Repo 實體，並注入 setting
    var repository = new MongoRepository(setting);

    // 新增課程
    var createResult = await repository.CreateCourse(new CourseModel
    {
        CourseId = "123",
        CourseName = "英文",
        Teacher = "Amy",
        Students = new List<Student>
        {
            new Student { Id = 1, Name = "Bob" },
        }
    });

    // 更新課程教師(Teacher) & 課程名稱(CourseName)
    var updateResult = await repository.UpdateCourse(new UpdateCourseModel
    {
        CourseId = "123",
        CourseName = "國文",
        Teacher = "Andy"
    });

    // 取得課程
    var course = await repository.GetCourse("123");

    // 取得所有課程
    var courses = await repository.GetAllCourse();

    // 刪除課程
    var deleteResult = await repository.DeleteCourse("123");
}

原始碼：連結

參考

使用 ASP.NET Core 與 MongoDB 建立 Web API

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