c# - 如何使用 Entity Framework 在 .NET Core 6 中播种数据？

Question

我知道如何使用我的类和创建一些初始数据的方法将数据播种到文件中带有旧.NET 5.0的数据库。startup.csSeederSeed()

public void Configure(IApplicationBuilder app, IHostingEnvironment env, Seeder seeder)
{
   seeder.Seed();

   ..............
   // other configurations
}

如何在.NET 6.0中执行此操作？没有地方可以将我的Seeder课程添加为参数。

Answer 1

我解决了一个类似的问题如下：

程序.cs (.NET 6)

...
builder.Services.AddScoped<IDbInitializer, DbInitializer>(); //can be placed among other "AddScoped" - above: var app = builder.Build();   

...    
SeedDatabase(); //can be placed above app.UseStaticFiles();
...    
    void SeedDatabase() //can be placed at the very bottom under app.Run()
    {
        using (var scope = app.Services.CreateScope())
        {
            var dbInitializer = scope.ServiceProvider.GetRequiredService<IDbInitializer>();
            dbInitializer.Initialize();
        }
    }

Answer 2

我以前从未使用过您的解决方案。这就是我正在做的，

public class DataContext: DbContext
{
    public DataContext(DbContextOptions options) : base(options)
    {
        
    }

    protected override void OnModelCreating(ModelBuilder modelBuilder)
    {
        base.OnModelCreating(modelBuilder);
        new DbInitializer(modelBuilder).Seed();
    }
    
    // Db sets
}

和

public class DbInitializer
{
    private readonly ModelBuilder modelBuilder;

    public DbInitializer(ModelBuilder modelBuilder)
    {
        this.modelBuilder = modelBuilder;
    }

    public void Seed()
    {
        modelBuilder.Entity<User>().HasData(
               new User(){ Id = 1.... },
               new User(){ Id = 2.... },

        );
    }
}

然后运行命令

dotnet ef migrations add .......

创建迁移文件

和

dotnet ef database update

更新数据库