如何解决 StringComparison.OrdinalIgnoreCase 和 LINQ 问题？

如何解决如何解决 StringComparison.OrdinalIgnoreCase 和 LINQ 问题？

代码如下： 控制器：

        //POST api/substances
        [HttpPost]
        [ServiceFilter(typeof(ValidateNameExistsAttribute<Substance>))]
        public ActionResult<SubstanceReadDto> CreateSubstance([FromBody]SubstanceSaveDto dto)
        {
            var substanceModel = _mapper.Map<Substance>(dto);
            _repository.CreateSubstance(substanceModel);
            _repository.SaveChanges();

            var substanceReadDto = _mapper.Map<SubstanceReadDto>(substanceModel);

            return CreatedAtRoute(nameof(GetSubstanceById),new {substanceReadDto.Id},substanceReadDto);
        }

过滤

using System.Linq;
using Microsoft.AspNetCore.Mvc;
using Microsoft.AspNetCore.Mvc.Filters;
using Pharmacy.Data;
using Pharmacy.Models;

namespace Pharmacy.Filters
{
    public class ValidateNameExistsAttribute<T> : IActionFilter where T : class,INameEntity
    {
        private readonly PharmacyContext _context;

        public ValidateNameExistsAttribute(PharmacyContext context)
        {
            _context = context;
        }

        public void OnActionExecuted(ActionExecutedContext context)
        {
        }

        public void OnActionExecuting(ActionExecutingContext context)
        {
            if (context.ActionArguments.ContainsKey("dto"))
            {
                var entity = new object();

                var dto = context.ActionArguments["dto"] as INameDto;
                if (dto == null)
                {
                    context.Result = new BadRequestObjectResult("Invalid request body");
                    return;
                }

                if (context.ActionArguments.ContainsKey("id"))
                {
                    var id = (int) context.ActionArguments["id"];
                    entity = _context.Set<T>().SingleOrDefault(it => String.Equals(it.Name,dto.Name,StringComparison.OrdinalIgnoreCase) && it.Id != id);
                }
                else
                {
                    entity = _context.Set<T>().SingleOrDefault(it => String.Equals(it.Name,StringComparison.OrdinalIgnoreCase));
                }

                if (entity != null)
                {
                    var problemDetails = new ProblemDetails
                    {
                        Title = "Duplicate resource",Detail = $"A record with provided name {dto.Name} already exists",Instance = context.HttpContext.Request.Path
                    };

                    context.Result = new ObjectResult(problemDetails)
                    {
                        StatusCode = 409
                    };
                }
            }
        }
    }
}

这是错误消息：代码有什么问题？

{ "type": "https://tools.ietf.org/html/rfc7231#section-6.6.1","title": "LINQ 表达式 'DbSet\r\n .Where(s => string.Equals(\r\na: s.Name,\r\nb: __dto_Name_0,\r\n compareType: OrdinalIgnoreCase))'无法翻译。要么以可翻译的形式重写查询，要么通过插入对 AsEnumerable()、AsAsyncEnumerable()、ToList() 或 ToListAsync() 的调用显式切换到客户端评估。请参阅{{3 }} 了解更多信息。”， “状态”：500， “详细信息”：“在 Microsoft.EntityFrameworkCore.Query.QueryableMethodTranslatingExpressionVisitor.g__CheckTranslated|8_0（ShapedQueryExpression 已翻译，c__displayClass8_0&）\r\n 在 Microsoft.EntityFrameworkCore.Query.QueryableMethodTranslatingExpressionVisitor.VisitMethodCall(MethodCallExpression method\CallExpression)\r\n EntityFrameworkCore.Query.RelationalQueryableMethodTranslatingExpressionVisitor.VisitMethodCall(MethodCallExpression methodCallExpression)\r\n 在 System.Linq.Expressions.MethodCallExpression.Accept(ExpressionVisitor 访问者)\r\n 在 System.Linq.Expressions.ExpressionVisitor.Visit(Expression 节点)\r\n n 在 Microsoft.EntityFrameworkCore.Query.QueryableMethodTranslatingExpressionVisitor.VisitMethodCall(MethodCallExpression methodCallExpression)\r\n 在 Microsoft.EntityFrameworkCore.Query.RelationalQueryableMethodTranslatingExpressionVisitor.VisitMethodCall(MethodCallExpression methodCallExpression)\r\n 在 System.Linq.Expressions.MethodCallre ssion.Accept(ExpressionVisitor 访问者)\r\n 在 System.Linq.Expressions.ExpressionVisitor.Visit(Expression 节点)\r\n 在 Microsoft.EntityFrameworkCore.Query.QueryCompilationContext.createqueryExecutor[TResult](表达式查询)\r\n在 Microsoft.EntityFrameworkCore.Storage.Database.CompileQuery[TResult]（表达式查询，布尔异步）\r\n 在 Microsoft.EntityFrameworkCore.Query.Internal.QueryCompiler.CompileQueryCore[TResult]（IDatabase 数据库，表达式查询，IModel 模型，布尔值async)\r\n 在 Microsoft.EntityFrameworkCore.Query.Internal.QueryCompiler.c__displayClass9_01.<Execute>b__0()\r\n at Microsoft.EntityFrameworkCore.Query.Internal.CompiledQueryCache.GetorAddQueryCore[TFunc](Object cacheKey,Func1 编译器)\r\n 在 Microsoft.EntityFrameworkCore.Query.Internal.CompiledQueryCache.GetorAddQuery[TResult](Object cacheKey,Func1 compiler)\r\n at Microsoft.EntityFrameworkCore.Query.Internal.QueryCompiler.Execute[TResult](Expression query)\r\n at Microsoft.EntityFrameworkCore.Query.Internal.EntityQueryProvider.Execute[TResult](Expression expression)\r\n at System.Linq.Queryable.SingleOrDefault[TSource](IQueryable1 source,Expression1 predicate)\r\n at Pharmacy.Filters.ValidateNameExistsAttribute1.OnActionExecuting(ActionExecutingContext context) in D:\.Pharmac Project\pharmac\Filters\ValidateNameExistsAttribute.cs:line 43\r\n at Microsoft.AspNetCore。 Mvc.Infrastructure.ControllerActionInvoker.Next(State&next,Scope&scope,Object&sta te,Boolean& isCompleted)\r\n 在 Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.InvokeNextActionFilterasync()\r\n--- 从上一个引发异常的位置的堆栈跟踪结束---\r\n 在 Microsoft .AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.Rethrow(ActionExecutedContextSealed context)\r\n 在 Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.Next(State& next,Scope& scope,Object& state,Boolean& isCompleted)\r\n 在 Microsoft。 AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.InvokeInnerFilterasync()\r\n--- 从上一个引发异常的位置的堆栈跟踪结束---\r\n 在 Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.g__Awaited|19_0 (ResourceInvoker invoker,Task lastTask,State next,Scope scope,Object state,Boolean isCompleted)\r\n 在 Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.g__Awaited|17_0(ResourceInvoker invoker,Task task,Idisposable scope)\r\n n 在 Microsoft.AspNetCore.Routin g.EndpointMiddleware.g__AwaitRequestTask|6_0(Endpoint endpoint,Task requestTask,ILogger logger)\r\n 在 Swashbuckle.AspNetCore.SwaggerUI.SwaggerUIMiddleware.Invoke(HttpContext httpContext)\r\n 在 Swashbuckle.AspNetCore.Swagger.SwaggerMiddleware.Inv HttpContext httpContext,ISwaggerProvider swaggerProvider)\r\n 在 Microsoft.AspNetCore.Authorization.AuthorizationMiddleware.Invoke(HttpContext context)\r\n 在 Microsoft.AspNetCore.Authentication.AuthenticationMiddleware.Invoke(HttpContext context)\r\n 在 Serilog.AspNetCore .RequestLoggingMiddleware.Invoke(HttpContext httpContext)\r\n 在 Microsoft.AspNetCore.Diagnostics.ExceptionHandlerMiddleware.g__Awaited|6_0(ExceptionHandlerMiddleware 中间件，HttpContext 上下文，任务任务)","traceId": "|9542c43b-43548354a97cc054。" }