系统.NotSupportedException:实体或复杂类型Model.申请人不能在LINQ到实体查询中构造

本文关键字：实体 LINQ 查询 不能 申请人 NotSupportedException 复杂 Model 类型 系统 | 更新日期: 2023-09-27 18:14:28

目前正在修复我的代码，直到出现此异常

System.NotSupportedException: The entity or complex type Model.APPLICANT' cannot be constructed in a LINQ to Entities query

这是我的控制器:

public IEnumerable<APPLICANT> GetApplicant()
{
    IEnumerable<APPLICANT> applicantdata = Cache.Get("applicants") as IEnumerable<APPLICANT>;

    if (applicantdata == null)
    {
        var applicantList = (from app in context.APPLICANTs
                             join a in context.Profiles
                             on app.Profile_id equals a.PROFILE_ID into output
                             from j in output.DefaultIfEmpty()
                             select new APPLICANT() { APPLICANT_ID = app.APPLICANT_ID, APPLICANT_LastName = (j == null ? app.APPLICANT_LastName : j.Applicant_LASTNAME) }).Take(1000).AsEnumerable().AsQueryable();
        applicantdata = applicantList.Where(v => !String.IsNullOrEmpty(v.APPLICANT_LastName)).AsEnumerable();

        if (applicantdata.Any())
        {
            Cache.Set("applicants", applicantdata, 30);
        }
    }
    return applicantdata;
}

异常出现在这一行

if (applicantdata.Any())

我希望有人能建议或能找到解决这个问题的方法。由于

系统.NotSupportedException:实体或复杂类型Model.申请人不能在LINQ到实体查询中构造

由于您不能在查询中创建非ef类型的新实例，您可以将查询分为两个部分。

首先得到数据

var data = from app in context.APPLICANTs
           join a in context.Profiles
             on app.Profile_id equals a.PROFILE_ID into output
           from j in output.DefaultIfEmpty()
           select new { 
             Id = app.APPLICANT_ID, 
             LastName = 
               (j == null ? app.APPLICANT_LastName : j.Applicant_LASTNAME) 
           };
var applicantData = data.Take(1000)
  .Where(v => !String.IsNullOrEmpty(v.APPLICANT_LastName));

然后初始化实例

var applicants = (from a in applicantData
                  select new APPLICANT() { 
                    APPLICANT_ID = a.Id, 
                    APPLICANT_LastName = a.LastName
                  }
                 ).AsEnumerable();
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