LINQ to Entities无法识别该方法,并且此方法无法转换为存储表达式

Question

我使用实体框架工作在我的数据库中调用了一些日期.但我的下面的代码给出了这个错误

LINQ to Entities无法识别方法'SchoolBreifcase.Compliance get_Item(Int32)'方法,并且此方法无法转换为商店表达式.

这是我的完整代码

FinancialCompliance financialCompliance = new FinancialCompliance();
            List<Compliance> compliance = null;
            if (HttpContext.Current.User.IsInRole("SchoolAdmin"))
            {

                compliance = datamodel.Compliances.Where(u => u.UserId == userId).OrderBy(c => c.AddedDate).ToList();

            }
            if (HttpContext.Current.User.IsInRole("User"))
            {
                compliance = datamodel.Compliances.Where(u => u.VerifierId == userId || u.OwnerId == userId).OrderBy(c => c.AddedDate).ToList();
            }
            if (compliance != null)
            {
                for (int i = 1; i < compliance.Count; i++)
                {
                    financialCompliance = datamodel.FinancialCompliances.Where(f => f.ComplianceId == compliance[i].ComplianceId).SingleOrDefault();
                    if (compliance.Count == i)
                    {
                        return financialCompliance;
                    }
                }
            }
            return financialCompliance;
        }

这一行给出了这个错误:

financialCompliance = datamodel.FinancialCompliances.Where(f => f.ComplianceId == compliance[i].ComplianceId).SingleOrDefault();

没有帮助堆栈过流回答 我在这个堆栈溢出站点找到了一些答案

LINQ to Entities无法识别该方法

等等.但对我没有帮助.所以我问了这个问题.请不要因为已经被问到的原因而关闭这个问题

Answer 1

您需要创建一个变量来引用,compliance[i].ComplianceId然后再使用它.

for (int i = 1; i < compliance.Count; i++)
{
    var complianceId = compliance[i].ComplianceId;
    financialCompliance = datamodel.FinancialCompliances.Where(f => f.ComplianceId == complianceId ).SingleOrDefault();
    if (compliance.Count == i)
    {
        return financialCompliance;
    }
}

Answer 2

这是关于compliance[i].ComplianceId.首先创建一个变量:

var id = compliance[i].ComplianceId;

financialCompliance = datamodel.FinancialCompliances
                      .Where(f => f.ComplianceId == id).SingleOrDefault();