Abp Development Flow

public class Book : AggregateRoot<Guid>
{
    public string Name { get; private set; }
    public decimal Price { get; private set; }
    public Guid AuthorId { get; private set; }

    protected Book() { }

    public Book(Guid id, string name, decimal price, Guid authorId) : base(id)
    {
        Name = Check.NotNullOrWhiteSpace(name, nameof(name));
        SetPrice(price);
        AuthorId = authorId;
    }

    public void SetPrice(decimal price)
    {
        Price = Check.Range(price, nameof(price), 0, 9999);
    }
}

public static class BookConsts
{
    public const int MaxNameLength = 128;
}

public enum BookType
{
    Novel,
    Science,
    Biography
}

// Only if custom queries are needed
public interface IBookRepository : IRepository<Book, Guid>
{
    Task<Book> FindByNameAsync(string name);
}

public DbSet<Book> Books { get; set; }

builder.Entity<Book>(b =>
{
    b.ToTable(MyProjectConsts.DbTablePrefix + "Books", MyProjectConsts.DbSchema);
    b.ConfigureByConvention();
    b.Property(x => x.Name).IsRequired().HasMaxLength(BookConsts.MaxNameLength);
    b.HasIndex(x => x.Name);
});

public class BookRepository : EfCoreRepository<MyDbContext, Book, Guid>, IBookRepository
{
    public BookRepository(IDbContextProvider<MyDbContext> dbContextProvider)
        : base(dbContextProvider)
    {
    }

    public async Task<Book> FindByNameAsync(string name)
    {
        return await (await GetDbSetAsync())
            .FirstOrDefaultAsync(b => b.Name == name);
    }
}

// DTOs
public class BookDto : EntityDto<Guid>
{
    public string Name { get; set; }
    public decimal Price { get; set; }
    public Guid AuthorId { get; set; }
}

public class CreateBookDto
{
    [Required]
    [StringLength(BookConsts.MaxNameLength)]
    public string Name { get; set; }

    [Range(0, 9999)]
    public decimal Price { get; set; }

    [Required]
    public Guid AuthorId { get; set; }
}

// Service Interface
public interface IBookAppService : IApplicationService
{
    Task<BookDto> GetAsync(Guid id);
    Task<PagedResultDto<BookDto>> GetListAsync(PagedAndSortedResultRequestDto input);
    Task<BookDto> CreateAsync(CreateBookDto input);
}

[Mapper]
public partial class BookMapper
{
    public partial BookDto MapToDto(Book book);
    public partial List<BookDto> MapToDtoList(List<Book> books);
}

context.Services.AddSingleton<BookMapper>();

public class BookAppService : ApplicationService, IBookAppService
{
    private readonly IRepository<Book, Guid> _bookRepository; // Or IBookRepository
    private readonly BookMapper _bookMapper;

    public BookAppService(
        IRepository<Book, Guid> bookRepository,
        BookMapper bookMapper)
    {
        _bookRepository = bookRepository;
        _bookMapper = bookMapper;
    }

    public async Task<BookDto> GetAsync(Guid id)
    {
        var book = await _bookRepository.GetAsync(id);
        return _bookMapper.MapToDto(book);
    }

    [Authorize(MyProjectPermissions.Books.Create)]
    public async Task<BookDto> CreateAsync(CreateBookDto input)
    {
        var book = new Book(
            GuidGenerator.Create(),
            input.Name,
            input.Price,
            input.AuthorId
        );

        await _bookRepository.InsertAsync(book);
        return _bookMapper.MapToDto(book);
    }
}

{
  "Book": "Book",
  "Books": "Books",
  "BookName": "Name",
  "BookPrice": "Price"
}

public static class MyProjectPermissions
{
    public static class Books
    {
        public const string Default = "MyProject.Books";
        public const string Create = Default + ".Create";
    }
}

public class BookAppService_Tests : MyProjectApplicationTestBase
{
    private readonly IBookAppService _bookAppService;

    public BookAppService_Tests()
    {
        _bookAppService = GetRequiredService<IBookAppService>();
    }

    [Fact]
    public async Task Should_Create_Book()
    {
        var result = await _bookAppService.CreateAsync(new CreateBookDto
        {
            Name = "Test Book",
            Price = 19.99m
        });

        result.Id.ShouldNotBe(Guid.Empty);
        result.Name.ShouldBe("Test Book");
    }
}