我正在运行WebAPI
I'm running a WebAPI,
Asp.Net Core 3.1 Automapper: 9.0 Automapper.Extensions.ExpressionMapping: 3.1我的LocaleDto PK是2 FK的复合键- LanguageCode 和 CountryCode
My LocaleDto PK is a composite key of 2 FK - LanguageCode and CountryCode
public class LocaleDto { [Key, ForeignKey(nameof(Language)), Column(Order = 0)] public string LanguageCode { get; set; } public LanguageDto Language { get; set; } [Key, ForeignKey(nameof(Country)), Column(Order = 1)] public string CountryCode { get; set; } public CountryDto Country { get; set; } }我想将LocaleDto映射到LocaleViewModel,其中 Id 是基于以下模式 languageCode-CountryCode 构建的. en-GB
I would like to map LocaleDto to LocaleViewModel, where Id is build based on the following pattern languageCode-CountryCode ie. en-GB
public class LocaleViewModel { public string Id {get;set;} public string LanguageCode { get; set; } public LanguageViewModel Language { get; set; } public string CountryCode { get; set; } public CountryViewModel Country { get; set; } }当我使用静态助手方法将一个对象映射到另一个对象时,以下映射工作正常:
The following mapping works just fine when I map one object to another using a static helper method:
CreateMap<LocaleDto, LocaleViewModel>() .ForMember(dest => dest.Id, opt => opt.MapFrom(src => LocalisationHelper.ToLocaleCode(src.LanguageCode, src.CountryCode))); CreateMap<LocaleViewModel, LocaleDto>() .ForMember(dest => dest.LanguageCode, src => src.MapFrom(x => x.LanguageCode)) .ForMember(dest => dest.CountryCode, src => src.MapFrom(x => x.CountryCode)); ... public static string ToLocaleCode(string languageCode, string countryCode) { if (!string.IsNullOrEmpty(languageCode) && !string.IsNullOrEmpty(countryCode)) { return $"{languageCode}-{countryCode}"; } return null; }但是当我映射表达式时,结果在LINQ中无法理解为SQL,因为它包含帮助程序LocalisationHelper.ToLocaleCode.
But when I map the expression, the result is not understandable in LINQ to SQL, cause it contains the helper LocalisationHelper.ToLocaleCode.
Expression<Func<LocaleViewModel, bool>> filter = x => x.Id == "en-GB"; var entityFilter = mapper.MapExpression<Expression<Func<LocaleDto, bool>>>(filter);检查EntityFilter:
{Param_0 => (ToLocaleCode(Param_0.LanguageCode, Param_0.CountryCode) == "en-GB")}例外
The LINQ expression 'DbSet<LocaleDto> .Where(l => LocalisationHelper.ToLocaleCode( languageCode: l.LanguageCode, countryCode: l.CountryCode) == "en-GB")' could not be translated. Either rewrite the query in a form that can be translated, or switch to client evaluation explicitly by inserting a call to either AsEnumerable(), AsAsyncEnumerable(), ToList(), or ToListAsync(). See go.microsoft/fwlink/?linkid=2101038 for more information.是否可以在Automapper中以不同方式映射这些属性,以便将结果转换为SQL,而无需切换到客户端评估?
推荐答案如果您尝试使用静态函数而不是静态函数,该怎么办
What if you tried instead of using a static function evaluate the expression directly
CreateMap<LocaleDto, LocaleViewModel>() .ForMember(dest => dest.Id, opt => opt.MapFrom(src => src.LanguageCode + "-" + src.CountryCode));更多推荐
自动映射器表达式将一个属性映射到多个属性
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