使用 AutoMapper 映射两个模型答案

【问题标题】：Mapping two models with AutoMapper使用 AutoMapper 映射两个模型
【发布时间】：2021-12-23 01:57:35
【问题描述】：

我有一个 Customer 模型，它与 Address 模型具有一对一的关系。我正在使用 AutoMapper 来映射这些值。我想使用我的 API 在数据库中创建一个新客户，理想情况下，它将根据提供给客户模型的信息插入一个新地址行。

这是我收到的实体框架核心的 SQL 异常： ---> Microsoft.Data.SqlClient.SqlException (0x80131904): Cannot insert the value NULL into column 'AddressId', table 'dbo.Customers'; column does not allow nulls. INSERT fails.

注意 - BaseEntity 仅包含 ID、并发检查等常见属性

客户模型：

public class Customer : BaseEntity
{
   public string FirstName { get; set; }
   public string LastName { get; set; }
   public string Phone { get; set; }
   public string Email { get; set; }
   public string UpdatedBy { get; set; }
   public DateTime? LastContact { get; set; }

   #region Navigation Properties
   public int? AddressId { get; set; }
   public string UserId { get; set; }
   public User User { get; set; }
   public virtual Address Address { get; set; }
   public virtual ICollection<Invoice> Invoices { get; set; }
   #endregion
}

我的地址模型：

public class Address : BaseEntity
{
   public string AddressLine1 { get; set; }
   public string AddressLine2 { get; set; }
   public string City { get; set; }
   public string State { get; set; }
   public string PostalCode { get; set; }

   #region Navigation Properties
   public virtual Customer Customer { get; set; }
   #endregion
}

我对请求使用了一个 DTO 类，如下：

public class CustomerCreateDto
{
   public string FirstName { get; set; }
   public string LastName { get; set; }
   public string Phone { get; set; }
   public string Email { get; set; }
   public string AddressLine1 { get; set; }
   public string AddressLine2 { get; set; }
   public string City { get; set; }
   public string State { get; set; }
   public string PostalCode { get; set; }
   public string UserId { get; set; }
}

AddressDto:

public class AddressDto : BaseEntity
{
   [Required]
   public string AddressLine1 { get; set; }
   public string AddressLine2 { get; set; }
   [Required]
   public string City { get; set; }
   public string State { get; set; }
   [Required]
   [DataType(DataType.PostalCode)]
   public string PostalCode { get; set; }
}

CustomerDto

public class CustomerDto : BaseEntity
{
   public string FirstName { get; set; }
   public string LastName { get; set; }
   public string Phone { get; set; }
   public string Email { get; set; }
   public string UserId { get; set; }
   public int AddressId { get; set; }
   public string UpdatedBy { get; set; }
   public DateTime? LastContact { get; set; }
   public virtual UserDto User { get; set; }
   public virtual AddressDto Address { get; set; }
   public virtual ICollection<InvoiceDto> Invoices { get; set; }
}

这是 AutoMapper 的配置

public class MappingConfiguration : Profile
{
   public MappingConfiguration()
   {
      CreateMap<AddressDto, Address>().ReverseMap();
      CreateMap<CustomerDto, Customer>().ForMember(dst => dst.UserId,
       opt => opt.MapFrom(src => src.User.Id)).ForMember(dst => 
       dst.Address, 
       opt => opt.MapFrom(src => src.Address)).ReverseMap();
      CreateMap<CustomerCreateDto, Customer>().ReverseMap();
    }
}

这里是Controller方法。我知道我可以通过使用addressDto 对象（如customer.Address = address）手动设置值来做到这一点，但我想看看是否有更好的方法

[HttpPost]
public async Task < IActionResult > Create([FromBody] CustomerCreateDto customerDto) 
{
   if (customerDto == null || !ModelState.IsValid) {
        return BadRequest(ModelState);
   }

   var addressDto = new AddressDto {
        AddressLine1 = customerDto.AddressLine1,
        AddressLine2 = customerDto.AddressLine2,
        City = customerDto.City,
        State = customerDto.State,
        PostalCode = customerDto.PostalCode,
        CreatedDate = DateTime.Now,
    };

    var user = await _userManager.FindByIdAsync(customerDto.UserId);
    var address = _mapper.Map<Address>(addressDto);
    var customer = _mapper.Map<Customer>(customerDto);
    
    customer.CreatedDate = DateTime.Now;

     var result = await _customerRepository.CreateAsync(customer);
     if (result) return Created("Created", new { customer });
     // if we got this far it means the request failed
     return new 
       StatusCodeResult(StatusCodes.Status500InternalServerError);
}

【问题讨论】：

AutoMapper 将您的 DTO 映射到实体中，但它不知道如何填充导航属性。所以你必须创建并保存地址（_addressRepo.CreateAsync(address)）并分配这个对象customer.Address = address。您可以使用 AutoMapper 自动执行此操作，但代码有点讨厌
您可以添加导航。道具。进入 DTO。在映射器方面，您可以处理映射。
我没有看到CustomerCreateDto 的任何映射。同时，我看到CustomerDto 和AddressDto 的映射未在此处显示。那么问题/问题到底是什么？
我已经添加了这些

标签： c# entity-framework-core automapper relationship ef-core-5.0

【解决方案1】：

我正在寻找的功能是通过将 CustomerCreateDto 更改为：

public class CustomerCreateDto
{
   public string FirstName { get; set; }
   public string LastName { get; set; }
   public string Phone { get; set; }
   public string Email { get; set; }
   public string UserId { get; set; }
   public virtual AddressDto Address { get; set; }
}

映射配置：

public class MappingConfiguration : Profile
{
   public MappingConfiguration()
   {
      CreateMap<AddressDto, Address>().ReverseMap();
      CreateMap<CustomerDto, Customer>().ForMember(dst => dst.UserId,
        opt => opt.MapFrom(src => src.User.Id));
      CreateMap<CustomerCreateDto, Customer>().ForMember(dst => dst.Address,
        opt => opt.MapFrom(src => src.Address)).ReverseMap().ReverseMap();
    }
}

我的控制器：

[HttpPost]
public async Task<IActionResult> Create([FromBody] CustomerCreateDto customerDto) 
{
   if (customerDto == null || !ModelState.IsValid) {
        return BadRequest(ModelState);
   }
   var customer = _mapper.Map<Customer>(customerDto);
    
   customer.CreatedDate = DateTime.Now;

   var result = await _customerRepository.CreateAsync(customer);
   if (result) return Created("Created", new { customer });

   return new StatusCodeResult(StatusCodes.Status500InternalServerError);
}

【讨论】：