如何在Entity Framework Core cli工具中使用dotnet 6 minimal API的配置

Question

如何在Entity Framework Core cli工具中使用dotnet 6 minimal API的配置

c#asp.net-coreentity-framework-core.net-6.0

7

我正在使用EF Core作为数据库访问构建API，目前在dotnet 6 RC1上进行。我想使用dotnet cli工具来管理迁移（创建、更新数据库等），但是这些工具与模板中的minimal API不兼容。

以下是我的Program.cs文件：

void ConfigureApp(WebApplication webApplication)
{
    // Configure the HTTP request pipeline.
    if (webApplication.Environment.IsDevelopment())
    {
        webApplication.UseSwagger();
        webApplication.UseSwaggerUI(c => c.SwaggerEndpoint("/swagger/v1/swagger.json", "Eyespert.Server v1"));
    }

    webApplication.UseHttpsRedirection();

    webApplication.UseAuthentication();
    webApplication.UseAuthorization();

    webApplication.MapControllers();
}

void RegisterServices(WebApplicationBuilder builder)
{
    builder.Services.AddControllers();
    builder.Services.AddSwaggerGen(c =>
    {
        c.SwaggerDoc("v1", new() { Title = "App", Version = "v1" });
    });
    
    builder.Services.AddDbContext<MyContext>(opt =>
    {
        string connectionString = builder.Configuration.GetConnectionString("MyConnectionString");
        opt.UseNpgsql(connectionString);
    });
}

WebApplicationBuilder builder = WebApplication.CreateBuilder(args);

RegisterServices(builder);

WebApplication app = builder.Build();

ConfigureApp(app);

app.Run();

如果那段代码使用了Program/Startup类组合和旧的构建器，我可以在控制台中输入dotnet ef migrations add InitialCreate，该工具会读取appsettings.development.json（即使它与上下文不同），并在正确的数据库上运行迁移。但是，在最小API样式中，情况并非如此。

作为解决方法，我创建了一个设计时上下文工厂。

public class DesignTimeDbContextFactory : IDesignTimeDbContextFactory<MyContext>
    {
        public MyContextCreateDbContext(string[] args)
        {
            DbContextOptionsBuilder<MyContext> dbContextOptionsBuilder =
                new();

            dbContextOptionsBuilder.UseNpgsql(@"myconnectionstring");

            Console.WriteLine("Creating default MyContext");
            
            return new MyContext(dbContextOptionsBuilder.Options);
        }
    }

您可以看到，我硬编码了连接字符串。我知道可以构造ConfigurationBuilder并使用相对路径来找到正确的json文件，并使用它来查找连接字符串，但这感觉像是一个肮脏的hack。

在dotnet 6中，最好的方法是什么？

- Krzysztof Skowronek

1

“用dotnet 6怎么做是最好的方式？” 目前还没有net6和EFC6。只有一些预览版、RC或者其他他们称之为的版本。重要的是它们还没有发布。因此，你不能期望有文档或者EFC工具可用等。当它们发布时，很可能会更新支持的设计时DbContext创建模式的文档（如果有的话）。在那之前，就使用现有的吧。 - Ivan Stoev

1个回答

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可以查看英文原文，
原文链接

- MestreDosMagros · Accepted Answer

我使用EFCore Context创建了一个MinimalAPI项目，它运行良好，没有发生任何重大问题，除了更新ef工具cli等，见完整项目:

MinimalApi.csproj

<Project Sdk="Microsoft.NET.Sdk.Web">

  <PropertyGroup>
    <TargetFramework>net6.0</TargetFramework>
    <Nullable>enable</Nullable>
    <ImplicitUsings>enable</ImplicitUsings>
    <LangVersion>Preview</LangVersion>
  </PropertyGroup>

  <ItemGroup>
    <PackageReference Include="Microsoft.EntityFrameworkCore.Design" Version="6.0.0-rc.1.21452.10">
      <PrivateAssets>all</PrivateAssets>
      <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
    </PackageReference>
    <PackageReference Include="Microsoft.EntityFrameworkCore.Tools" Version="6.0.0-rc.1.21452.10">
      <PrivateAssets>all</PrivateAssets>
      <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
    </PackageReference>
    <PackageReference Include="Swashbuckle.AspNetCore" Version="6.1.5" />
  </ItemGroup>

  <ItemGroup>
    <ProjectReference Include="..\Infra\Infra.csproj" />
  </ItemGroup>

</Project>

Program.cs

using Infra;
using Microsoft.EntityFrameworkCore;

var builder = WebApplication.CreateBuilder(args);

builder.Services.AddDbContext<Context>(opts =>
{
    var connString = builder.Configuration.GetConnectionString("MyConnectionString");
    opts.UseSqlServer(connString, options =>
    {
        options.MigrationsAssembly(typeof(Context).Assembly.FullName.Split(',')[0]);
    });
});

await using var app = builder.Build();

if (app.Environment.IsDevelopment())
{
    app.UseDeveloperExceptionPage();
}

app.MapGet("/", (Func<string>)(() => "Hello World!"));

await app.RunAsync();

Infra.csproj

<Project Sdk="Microsoft.NET.Sdk">

  <PropertyGroup>
    <TargetFramework>net6.0</TargetFramework>
    <ImplicitUsings>enable</ImplicitUsings>
    <Nullable>enable</Nullable>
    <LangVersion>Preview</LangVersion>
  </PropertyGroup>

  <ItemGroup>
    <PackageReference Include="Microsoft.EntityFrameworkCore" Version="6.0.0-rc.1.21452.10" />
    <PackageReference Include="Microsoft.EntityFrameworkCore.Design" Version="6.0.0-rc.1.21452.10">
      <PrivateAssets>all</PrivateAssets>
      <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
    </PackageReference>
    <PackageReference Include="Microsoft.EntityFrameworkCore.SqlServer" Version="6.0.0-rc.1.21452.10" />
    <PackageReference Include="Microsoft.EntityFrameworkCore.Tools" Version="6.0.0-rc.1.21452.10">
      <PrivateAssets>all</PrivateAssets>
      <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
    </PackageReference>
  </ItemGroup>

  <ItemGroup>
    <ProjectReference Include="..\Domain\Domain.csproj" />
  </ItemGroup>

</Project>

Infra.Context.cs

：基础设施层的上下文文件。

using Domain;
using Microsoft.EntityFrameworkCore;

namespace Infra
{
    public class Context : DbContext
    {

        public Context(DbContextOptions options) : base(options)
        {
        }

        protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
        {
        }

        protected override void OnModelCreating(ModelBuilder modelBuilder)
        {
        }

        public DbSet<MyEntity> MyEntities { get; set; }
    }
}

Domain.csproj

<Project Sdk="Microsoft.NET.Sdk">

  <PropertyGroup>
    <TargetFramework>net6.0</TargetFramework>
    <ImplicitUsings>enable</ImplicitUsings>
    <Nullable>enable</Nullable>
    <LangVersion>Preview</LangVersion>
  </PropertyGroup>

</Project>

实体示例（MyEntity.cs）

using System.ComponentModel.DataAnnotations;
using System.ComponentModel.DataAnnotations.Schema;

namespace Domain
{
    public class MyEntity
    {
        [Key]
        [DatabaseGenerated(DatabaseGeneratedOption.Identity)]
        public Guid Id { get; set; }
        public string Name { get; set; }
        public string Value { get; set; }
    }
}

在NuGet包管理器上创建迁移。

PM> Add-Migration InitialMigration
Build started...
Build succeeded.
Microsoft.EntityFrameworkCore.Infrastructure[10403]
      Entity Framework Core 6.0.0-rc.1.21452.10 initialized 'Context' using provider 'Microsoft.EntityFrameworkCore.SqlServer:6.0.0-rc.1.21452.10' with options: MigrationsAssembly=Infra

在 NuGet 包管理器中更新数据库

PM> Update-Database
Build started...
Build succeeded.
Microsoft.EntityFrameworkCore.Infrastructure[10403]
      Entity Framework Core 6.0.0-rc.1.21452.10 initialized 'Context' using provider 'Microsoft.EntityFrameworkCore.SqlServer:6.0.0-rc.1.21452.10' with options: MigrationsAssembly=Infra 
Microsoft.EntityFrameworkCore.Database.Command[20101]
      Executed DbCommand (2,338ms) [Parameters=[], CommandType='Text', CommandTimeout='60']
      CREATE DATABASE [MinimalApiDb];
Microsoft.EntityFrameworkCore.Database.Command[20101]
      Executed DbCommand (933ms) [Parameters=[], CommandType='Text', CommandTimeout='60']
      IF SERVERPROPERTY('EngineEdition') <> 5
      BEGIN
          ALTER DATABASE [MinimalApiDb] SET READ_COMMITTED_SNAPSHOT ON;
      END;
Microsoft.EntityFrameworkCore.Database.Command[20101]
      Executed DbCommand (29ms) [Parameters=[], CommandType='Text', CommandTimeout='30']
      SELECT 1
Microsoft.EntityFrameworkCore.Database.Command[20101]
      Executed DbCommand (18ms) [Parameters=[], CommandType='Text', CommandTimeout='30']
      CREATE TABLE [__EFMigrationsHistory] (
          [MigrationId] nvarchar(150) NOT NULL,
          [ProductVersion] nvarchar(32) NOT NULL,
          CONSTRAINT [PK___EFMigrationsHistory] PRIMARY KEY ([MigrationId])
      );
Microsoft.EntityFrameworkCore.Database.Command[20101]
      Executed DbCommand (3ms) [Parameters=[], CommandType='Text', CommandTimeout='30']
      SELECT 1
Microsoft.EntityFrameworkCore.Database.Command[20101]
      Executed DbCommand (17ms) [Parameters=[], CommandType='Text', CommandTimeout='30']
      SELECT OBJECT_ID(N'[__EFMigrationsHistory]');
Microsoft.EntityFrameworkCore.Database.Command[20101]
      Executed DbCommand (5ms) [Parameters=[], CommandType='Text', CommandTimeout='30']
      SELECT [MigrationId], [ProductVersion]
      FROM [__EFMigrationsHistory]
      ORDER BY [MigrationId];
Microsoft.EntityFrameworkCore.Migrations[20402]
      Applying migration '20211001150743_InitialMigration'.
Applying migration '20211001150743_InitialMigration'.
Microsoft.EntityFrameworkCore.Database.Command[20101]
      Executed DbCommand (176ms) [Parameters=[], CommandType='Text', CommandTimeout='30']
      CREATE TABLE [MyEntities] (
          [Id] uniqueidentifier NOT NULL,
          [Name] nvarchar(max) NOT NULL,
          [Value] nvarchar(max) NOT NULL,
          CONSTRAINT [PK_MyEntities] PRIMARY KEY ([Id])
      );
Microsoft.EntityFrameworkCore.Database.Command[20101]
      Executed DbCommand (23ms) [Parameters=[], CommandType='Text', CommandTimeout='30']
      INSERT INTO [__EFMigrationsHistory] ([MigrationId], [ProductVersion])
      VALUES (N'20211001150743_InitialMigration', N'6.0.0-rc.1.21452.10');
Done.
PM>

使用 dotnet ef 工具需要更新到最新的 RC 版本，以匹配您的项目设计器/工具。

dotnet tool update --global dotnet-ef --version 6.0.0-rc.1.21452.10

请注意，这是您在项目软件包中使用的相同版本。

通过 ef 工具命令行界面创建迁移

PS D:\Repositorios\MinimalApi\MinimalApi> dotnet ef migrations add eftoolsmigration -s "D:\Repositorios\MinimalApi\MinimalApi\MinimalApi.csproj" -p "D:\Repositorios\MinimalApi\Infra\Infra.csproj"

Build started...
Build succeeded.
info: Microsoft.EntityFrameworkCore.Infrastructure[10403]
      Entity Framework Core 6.0.0-rc.1.21452.10 initialized 'Context' using provider 'Microsoft.EntityFrameworkCore.SqlServer:6.0.0-rc.1.21452.10' with options: MigrationsAssembly=Infra
Done. To undo this action, use 'ef migrations remove'
PS D:\Repositorios\MinimalApi\MinimalApi>

使用 EF 工具 CLI 更新数据库

 dotnet ef database update -s "D:\Repositorios\MinimalApi\MinimalApi\MinimalApi.csproj" -p "D:\Repositorios\MinimalApi\Infra\Infra.csproj"

-s 是你的启动项目路径
-p 是目标项目路径（上下文配置所在的位置）

自动生成的Migrations文件夹

最终项目结构

创建的数据库

注意，您将需要在软件包管理器上设置“包括预发行版”，以获取与 .Net 6 兼容的版本
请注意，您正在使用PostgreSQL数据库，它必须具有与EF Core 6.xxx兼容的客户端

已安装的运行时和SDK（仅针对.NET 6进行澄清）

PS C:\Users\Daniel> dotnet --list-runtimes
Microsoft.NETCore.App 6.0.0-rc.1.21451.13 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
Microsoft.WindowsDesktop.App 6.0.0-rc.1.21451.3 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]

PS C:\Users\Daniel> dotnet --list-sdks
6.0.100-rc.1.21463.6 [C:\Program Files\dotnet\sdk]