为什么LINQ到实体无​​法识别方法'System.String的ToString（）？ [英] Why LINQ to Entities does not recognize the method 'System.String ToString()?

问题描述

里面MVC3 Web应用程序获取错误。
LINQ到实体无​​法识别方法'System.String的ToString（）方法，而这种方法不能被翻译成店前pression。

当我尝试获取使用EF从查询值：

 公共类DataRepository
    {
        公共mydataEntities1的DbContext =新mydataEntities1（）;        公开名单＆LT; SelectListItem＆GT; GetPricingSecurityID（）
        {
        VAR pricingSecurityID =（从米dbContext.Reporting_DailyNAV_Pricing
                                     选择新SelectListItem
                                         {
                                                文本= m.PricingSecurityID.ToString（），
                                                值= m.PricingSecurityID.ToString（）
                                         }）;        返回pricingSecurityID.ToList（）;
        }
    }
 

解决方案

这不能转换为SQL。我想，在理论上，它可以，但没有实现。

您只需要执行您的投影你有你的结果后：

  VAR pricingSecurityID =（从dbContext.Reporting_DailyNAV_Pricing米
                                     选择m.PricingSecurityID）.AsEnumerable（）
    。选择（X =＆gt;新建SelectListItem的{text = x.ToString（），值= x.ToString（）}）;
 

Getting error inside MVC3 web application. LINQ to Entities does not recognize the method 'System.String ToString()' method, and this method cannot be translated into a store expression.

when i try to fetch values using EF from query :

public class DataRepository
    {
        public mydataEntities1 dbContext = new mydataEntities1();

        public List<SelectListItem> GetPricingSecurityID()
        {
        var pricingSecurityID = (from m in dbContext.Reporting_DailyNAV_Pricing
                                     select new SelectListItem
                                         {
                                                Text = m.PricingSecurityID.ToString(),
                                                Value = m.PricingSecurityID.ToString()
                                         });

        return pricingSecurityID.ToList();
        }
    }

解决方案

That can't be converted to SQL. I guess, in theory, it could, but isn't implemented.

You just need to perform your projection after you have your results:

var pricingSecurityID = (from m in dbContext.Reporting_DailyNAV_Pricing
                                     select m.PricingSecurityID).AsEnumerable()
    .Select(x => new SelectListItem{ Text = x.ToString(), Value = x.ToString() });

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