Question

我有以下几种模型：

用户：

public class User
{
    [DatabaseGenerated(DatabaseGeneratedOption.Identity)]
    public int Id { get; set; }

    public string Name { get; set; }

    public DateTime CreatedAt { get; set; }

    public DateTime UpdatedAt { get; set; }

    public string SocialId { get; set; }

    public string AccessToken { get; set; }

    public string RefreshToken { get; set; }

    public DateTime ExpirationAccess { get; set; }

    public DateTime ExpirationRefresh { get; set; }

    public string AuthType { get; set; }

    public decimal Money { get; set; }

    public User()
    {
        CreatedAt = DateTime.UtcNow;
        UpdatedAt = DateTime.UtcNow;

        AccessToken = Guid.NewGuid().ToString();
        RefreshToken = Guid.NewGuid().ToString();

        ExpirationAccess = DateTime.UtcNow.AddDays(1);
        ExpirationRefresh = DateTime.UtcNow.AddMonths(1);
    }
}

食谱：

public class Recipe
{
    [DatabaseGenerated(DatabaseGeneratedOption.Identity)]
    public int Id { get; set; }

    public string Name { get; set; }

    public User Author { get; set; }

    public int LikesCount { get; set; }

    public int DislikesCount { get; set; }

    public int Time { get; set; }

    public ICollection<Ingridient> Ingridients { get; set; }

    public ICollection<RecipeStep> Steps { get; set; }

    public Category Category { get; set; }

    public int ServingsCount { get; set; }

    public int Image { get; set; }

    public decimal Price { get; set; }

    public DateTime CreatedAt { get; set; }

    public DateTime UpdatedAt { get; set; }

    public Recipe()
    {
        CreatedAt = DateTime.UtcNow;
        UpdatedAt = DateTime.UtcNow;
    }
}

所有型号都在这里。

运行dotnet ef migrations add InitialMigration时，我只能迁移一个表Users。这是生成的迁移的文本：

public partial class InitialMigration : Migration
{
    protected override void Up(MigrationBuilder migrationBuilder)
    {
        migrationBuilder.CreateTable(
            name: "Users",
            columns: table => new
            {
                Id = table.Column<int>(nullable: false)
                    .Annotation("Npgsql:ValueGenerationStrategy", NpgsqlValueGenerationStrategy.SerialColumn),
                Name = table.Column<string>(nullable: true),
                CreatedAt = table.Column<DateTime>(nullable: false),
                UpdatedAt = table.Column<DateTime>(nullable: false),
                SocialId = table.Column<string>(nullable: true),
                AccessToken = table.Column<string>(nullable: true),
                RefreshToken = table.Column<string>(nullable: true),
                ExpirationAccess = table.Column<DateTime>(nullable: false),
                ExpirationRefresh = table.Column<DateTime>(nullable: false),
                AuthType = table.Column<string>(nullable: true),
                Money = table.Column<decimal>(nullable: false)
            },
            constraints: table =>
            {
                table.PrimaryKey("PK_Users", x => x.Id);
            });
    }

    protected override void Down(MigrationBuilder migrationBuilder)
    {
        migrationBuilder.DropTable(
            name: "Users");
    }
}

它看起来像是仅对Users表的迁移。但是其余的呢？当我运行dotnet ef database update时，我只有一个表Users。

那怎么了？我是EF的新手，也许我不明白它的工作原理。您能描述一下如何从模型中生成所有表吗？

P.S。该平台是.Net Core 2.2.300。项目类型是Web API。数据库是PostgreSQL。

更新

我的数据库上下文是

public class ApplicationContext : DbContext
{
    private readonly string _connectionString;

    public ApplicationContext(IConfiguration configuration)
    {
        _connectionString = configuration.GetConnectionString("Recipes");
    }

    public DbSet<User> Users { get; set; }

    protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
    {
        optionsBuilder.UseNpgsql(_connectionString);
    }
}

我已经通过标准DI系统注入了

    public void ConfigureServices(IServiceCollection services)
    {
        services.AddMvc()
       .SetCompatibilityVersion(CompatibilityVersion.Version_2_2);

        services.AddEntityFrameworkNpgsql()
            .AddDbContext<ApplicationContext>()
            .BuildServiceProvider();

        services.AddSingleton<IAuthService, AuthService>();
    }

Answer 1

您已经在DbContext中添加了一组User。

public DbSet<User> Users { get; set; }

您尚未添加一组Recipe。这就是为什么要迁移User而不迁移Recipe的原因。为配方添加一个，然后通过反转并重新创建来重新生成迁移，或者添加另一个以使更改复杂化。

public DbSet<Recipe> Recipes { get; set; }

注意：您可以映射实体并进行迁移，而无需将DbSet<>添加到DbContext中，但这涉及在OnModelCreating中设置实体。

为什么在运行实体框架迁移后我只有一个表？

更新

1 个答案: