LINQ到实体无​​法识别方法“的Int32的Int32（System.String）'在MVC C＃方法 [英] LINQ to Entities does not recognize the method 'Int32 Int32(System.String)' method in MVC c#

问题描述

当我试图查询使用LINQ到实体我得到这个异​​常Databae语境。结果
           LINQ到实体无​​法识别方法的Int32的Int32（System.String）的方法，而这种方法不能被翻译成店前pression。

请帮忙。
由于提前

 如果（的Request.Form [登记]！= NULL）
                {
                    字符串[] =选择的Request.Form [注册]斯普利特（''）。                    如果（选择！= NULL）
                    {
                        如果（selected.Count（）！= 0）
                        {
                            INT K = 0;
                            的foreach（在选定的VAR项）
                            {
                                VAR ID = db.EnrollTrainee.Where（I =＆GT; i.TraineeID == Convert.ToInt32（项目[K]的ToString（））
                                         ＆功放;＆安培; i.TrainerID == Convert.ToInt32（会话[用户]的ToString（）））;
                                如果（ID！= NULL）
                                {
                                    的foreach（在ID VAR一）//获取异常这里
                                    {
                                        enroll.id = a.id;
                                        db.EnrollTrainee.Remove（登记）;
                                        db.SaveChanges（）;
                                    }
                                }
                                ķ++;
                            }
                        }
                    }
 

解决方案

你有没有尝试过做转换你做LINQ之前？

所以像这样的：

 的foreach（在选定的VAR项）
  {
        VAR tempId = Convert.ToInt32（项目[K]的ToString（））;
        VAR tempId2 = Convert.ToInt32（会话[用户]的ToString（））;
        变种的id = db.EnrollTrainee.Where（ⅰ= GT; i.TraineeID == tempId
                                     ＆功放;＆安培; i.TrainerID == tempId2）;
                            如果（ID！= NULL）
                            {
                                的foreach（在ID VAR一）//获取异常这里
                                {
                                    enroll.id = a.id;
                                    db.EnrollTrainee.Remove（登记）;
                                    db.SaveChanges（）;
                                }
                            }
                            ķ++;
                        }
 

When I am trying to Query Databae Context using Linq to Entities I am getting this Exception.
LINQ to Entities does not recognize the method 'Int32 Int32(System.String)' method, and this method cannot be translated into a store expression.

Please help. Thanks in Advance

                if (Request.Form["Enroll"] != null)
                {
                    string[] selected = Request.Form["Enroll"].Split(',');

                    if (selected != null)
                    {
                        if (selected.Count() != 0)
                        {
                            int k = 0;
                            foreach (var item in selected)
                            {
                                var id = db.EnrollTrainee.Where(i => i.TraineeID ==          Convert.ToInt32(item[k].ToString())
                                         && i.TrainerID == Convert.ToInt32(Session["user"].ToString()));
                                if (id != null)
                                {
                                    foreach (var a in id)//Getting Exception Here
                                    {
                                        enroll.id = a.id;
                                        db.EnrollTrainee.Remove(enroll);
                                        db.SaveChanges();                                           
                                    }
                                }
                                k++;
                            }
                        }
                    }

解决方案

Have you tried doing the conversion before you do the linq?

So like this:

  foreach (var item in selected)
  {
        var tempId = Convert.ToInt32(item[k].ToString());
        var tempId2 = Convert.ToInt32(Session["user"].ToString());
        var id = db.EnrollTrainee.Where(i => i.TraineeID == tempId         
                                     && i.TrainerID == tempId2);
                            if (id != null)
                            {
                                foreach (var a in id)//Getting Exception Here
                                {
                                    enroll.id = a.id;
                                    db.EnrollTrainee.Remove(enroll);
                                    db.SaveChanges();                                           
                                }
                            }
                            k++;
                        }

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