我在使用AutoMapper(版本5.1.1)投影和Linq OrderBy Child属性表达式时出现问题。我正在使用Entity Framework Core(版本1.0.0)。我收到以下错误:
“必须是可简化的节点”
我的DTO对象如下
public class OrganizationViewModel
{
public virtual int Id { get; set; }
[Display(Name = "Organization Name")]
public virtual string Name { get; set; }
public virtual bool Active { get; set; }
public virtual int OrganizationGroupId { get; set; }
public virtual string OrganizationGroupName { get; set; }
public virtual int StrategyId { get; set; }
public virtual string StrategyName { get; set; }
public virtual OrganizationGroupViewModel OrganizationGroup { get; set; }
}
public class OrganizationGroupViewModel
{
public virtual int Id { get; set; }
[Display(Name = "Organization Group Name")]
public virtual string Name { get; set; }
public virtual bool Active { get; set; }
}
我对应的实体模型如下:
public class Organization
{
public int Id { get; set; }
public string Name { get; set; }
public string TimeZone { get; set; }
public bool Active { get; set; }
//FKs
public int OrganizationGroupId { get; set; }
public int StrategyId { get; set; }
//Navigation
public virtual OrganizationGroup OrganizationGroup { get; set; }
public virtual Strategy Strategy { get; set; }
[JsonIgnore]
public virtual List<AppointmentReminder> AppointmentReminders { get; set; }
}
public class OrganizationGroup
{
public int Id { get; set; }
public string Name { get; set; }
public bool Active { get; set; }
public virtual List<Organization> Organizations { get; set; }
}
我的AutoMapper配置文件如下:
public class OrganizationMapperProfile : Profile
{
public OrganizationMapperProfile()
{
CreateMap<Task<Organization>, Task<OrganizationViewModel>>();
CreateMap<Organization, OrganizationViewModel>()
.ForMember(dest => dest.OrganizationGroupName, opt => opt.MapFrom(src => src.OrganizationGroup.Name));
CreateMap<OrganizationInput, Organization>()
.ForMember(x => x.Id, opt => opt.Ignore());
}
}
public class OrganizationGroupMapperProfile : Profile
{
public OrganizationGroupMapperProfile()
{
CreateMap<Task<OrganizationGroup>, Task<OrganizationGroupViewModel>>();
CreateMap<OrganizationGroup, OrganizationGroupViewModel>();
CreateMap<OrganizationGroupInput, OrganizationGroup>()
.ForMember(x => x.Id, opt => opt.Ignore());
}
}
当我运行以下语句时,我能够运行并获得前两个语句的结果:
var tmp = await _context.Organizations.Include(x => x.OrganizationGroup).OrderBy(x => x.OrganizationGroup.Name).ToListAsync();
var tmp4 = await _context.Organizations.Include(x => x.OrganizationGroup).OrderBy("OrganizationGroup.Name").ToListAsync();
但是当我添加ProjectTo时,我得到了上面列出的错误:
var tmp5 = await _context.Organizations.Include(x => x.OrganizationGroup).OrderBy(x => x.OrganizationGroup.Name).ProjectTo<OrganizationViewModel>().ToListAsync();
var tmp6 = await _context.Organizations.Include(x => x.OrganizationGroup).OrderBy("OrganizationGroup.Name").ProjectTo<OrganizationViewModel>().ToListAsync();
作为一些额外的信息,我能够使用Project处理父类的属性,例如:
var tmp7 = await _context.Organizations.Include(x => x.OrganizationGroup).OrderBy(x => x.Name).ProjectTo<OrganizationViewModel>().ToListAsync();
var tmp8 = await _context.Organizations.Include(x => x.OrganizationGroup).OrderBy("Name").ProjectTo<OrganizationViewModel>().ToListAsync();
之前有人遇到过这个问题吗?看起来我正在尝试做一些其他方面不支持的东西,那是设计的吗?感谢您的帮助/见解。
答案 0 :(得分:4)
看起来问题是由OrganizationGroup
类的OrganizationViewModel
属性引起的 - AutoMapper生成一个空检查,EF Core与您的OrderBy
组合不喜欢(I猜测只是目前EF Core中的许多错误之一)。它可以通过以下简单的手动投影查询轻松复制:
var tmp5a = _context.Organizations
.OrderBy(x => x.OrganizationGroup.Name)
.Select(e => new OrganizationViewModel
{
Id = e.Id,
OrganizationGroup = e.OrganizationGroup != null ? new OrganizationGroupViewModel
{
Id = e.OrganizationGroup.Id,
Name = e.OrganizationGroup.Name,
Active = e.OrganizationGroup.Active,
} : null,
})
.ToList();
要解决此问题,请将AutoMapper配置为不生成null
检查该属性,如下所示:
CreateMap<Organization, OrganizationViewModel>()
.ForMember(dest => dest.OrganizationGroup, opt => opt.AllowNull())
.ForMember(dest => dest.OrganizationGroupName, opt => opt.MapFrom(src => src.OrganizationGroup.Name));