ASP.NET6 + Mongo + OData

准备工作

• Docker环境
• Mongo数据库
• 配置Mongo数据库

ASP.NET6 集成Mongo

安装MongoDB.Driver

{     "Logging": {         "LogLevel": {             "Default": "Information",             "Microsoft.AspNetCore": "Warning"             }     },     "BookStoreDatabase": {         "ConnectionString": "mongodb://localhost",         "DatabaseName": "BookStore",         "BooksCollectionName": "Books"         },     "AllowedHosts": "*" } 

public class BookStoreDatabaseSettings {     public string ConnectionString { get; set; } = null!;      public string DatabaseName { get; set; } = null!;      public string BooksCollectionName { get; set; } = null!; } 

using MongoDB.Bson; using MongoDB.Bson.Serialization.Attributes;  namespace MongoExample.Models;  public class Book {     [BsonId]     [BsonRepresentation(BsonType.ObjectId)]     public string? Id { get; set; }      [BsonElement("Name")]     public string BookName { get; set; } = null!;           public decimal Price { get; set; }      public string Category { get; set; } = null!;      public string Author { get; set; } = null!; } 

using MongoDB.Driver; using MongoExample.Models; using Microsoft.Extensions.Options;  namespace MongoExample.Services;  public class BookService {     private readonly IMongoCollection<Book> _bookCollection;      public BookService(IOptions<BookStoreDatabaseSettings> bookStoreDatabaseSettings)     {         var mongoClient = new MongoClient("mongodb://admin:000000@localhost:27017");         var mongoDatabase = mongoClient.GetDatabase(bookStoreDatabaseSettings.Value.DatabaseName);         _bookCollection = mongoDatabase.GetCollection<Book>(bookStoreDatabaseSettings.Value.BooksCollectionName);     }      public async Task<List<Book>> GetBooksAsync() => await _bookCollection.Find(_ => true).ToListAsync();      public async Task<Book> GetBookAsync(string id) => await _bookCollection.Find(x=>x.Id == id).FirstOrDefaultAsync();      public async Task CreateAsync(Book book) => await _bookCollection.InsertOneAsync(book);      public async Task UpdateAsync(string id, Book updatedBook) => await _bookCollection.ReplaceOneAsync(x=>x.Id == id, updatedBook);      public async Task RemoveAsync(string id) => await _bookCollection.DeleteOneAsync(x=>x.Id ==id);  }  

using Microsoft.AspNetCore.Mvc; using Microsoft.AspNetCore.OData.Query; using MongoExample.Models; using MongoExample.Services;  namespace MongoExample.Controllers;  [ApiController] [Route("/api/[controller]")] public class BooksController : ControllerBase {     private readonly BookService _bookService;      public BooksController(BookService bookService)     {         this._bookService = bookService;     }      [HttpGet]     [EnableQuery]     public async Task<List<Book>> Get() => await _bookService.GetBooksAsync();      [HttpGet("{id:length(24)}")]     public async Task<ActionResult<Book>> GetBook(string id)     {         var book = await _bookService.GetBookAsync(id);         if (book == null)         {             return NotFound();         }          return book;     }      [HttpPost]     public async Task<ActionResult> Create(Book book)     {         await _bookService.CreateAsync(book);         return CreatedAtAction("Get", new { id = book.Id }, book);     }      [HttpPut("{id:length(24)}")]     public async Task<IActionResult> Update(string id, Book updatedBook)     {         var book = await _bookService.GetBookAsync(id);         if (book == null)         {             return NotFound();         }          updatedBook.Id = book.Id;         await _bookService.UpdateAsync(id, updatedBook);         return NoContent();     }      [HttpDelete("{id:length(24)}")]     public async Task<IActionResult> Delete(string id)     {         var book = await _bookService.GetBookAsync(id);         if (book == null)         {             return NotFound();         }          await _bookService.RemoveAsync(id);         return NoContent();     } } 

ASP.NET6 集成OData

VS22022基于.NET6基础上创建的asp.net core web api模板已经合并了Startup和Program类， 所有的服务注入，中间件注入都合并在了Program类中， 好久没写C#了，这个类这次变化有点大。
安装OData

合并后的模板只有Program.cs类，没有了Startup类，也就是之前的服务注入都是通过ConfigServices方法，IServiceCollection实现。 如果不习惯的话也可以自己手动创建一个Startup类，然后在Program类中调用该类。

using Microsoft.AspNetCore.OData; using MongoExample.Models; using MongoExample.Services;  var builder = WebApplication.CreateBuilder(args);  builder.Services.AddControllers(); builder.Services.AddEndpointsApiExplorer(); builder.Services.AddSwaggerGen(); builder.Services.Configure<BookStoreDatabaseSettings>(builder.Configuration.GetSection("BookStoreDatabase")); builder.Services.AddSingleton<BookService>(); //这里注入OData查询方法 builder.Services.AddControllers().AddOData(options => options.Select().Filter().OrderBy());  var app = builder.Build();  if (app.Environment.IsDevelopment()) {     app.UseSwagger();     app.UseSwaggerUI(); }  app.UseAuthorization();  app.MapControllers();  app.Run();  

测试OData Query

查询Category和BookName字段
http://localhost:5220/api/books?$select=Category,BookName
响应JSON值

[{"Category":"Computer","BookName":"Design Patters"},{"Category":"Software","BookName":"Java In Action"},{"Category":"Software","BookName":"C# In Action"}] 

查询Category和BookName字段并且用Category倒叙排列

[{"Category":"Software","BookName":"Java In Action"},{"Category":"Software","BookName":"C# In Action"},{"Category":"Computer","BookName":"Design Patters"}]