LINQ to Entities不支持指定的类型成员。只支持初始化器，实体成员和实体导航属性 [英] The specified type member is not supported in LINQ to Entities. Only initializers, entity members, and entity navigation properties are supported

问题描述

var result =
    (from bd in context.tblBasicDetails
     from pd in context.tblPersonalDetails.Where(x => x.UserId == bd.UserId).DefaultIfEmpty()
     from opd in context.tblOtherPersonalDetails.Where(x => x.UserId == bd.UserId).DefaultIfEmpty()
     select new clsProfileDate()
     {
         DOB = pd.DOB
     });

foreach (clsProfileDate prod in result)
{
    prod.dtDOB = !string.IsNullOrEmpty(prod.DOB) ? Convert.ToDateTime(prod.DOB) : DateTime.Today;
    int now = int.Parse(DateTime.Today.ToString("yyyyMMdd"));
    int dob = int.Parse(prod.dtDOB.ToString("yyyyMMdd"));
    string dif = (now - dob).ToString();
    string age = "0";
    if (dif.Length > 4)
    age = dif.Substring(0, dif.Length - 4);
    prod.Age = Convert.ToInt32(age);
}

GetFinalResult(result);

---

---

protected void GetFinalResult(IQueryable<clsProfileDate> result)
{
    int from;
    bool bfrom = Int32.TryParse(ddlAgeFrom.SelectedValue, out from);
    int to;
    bool bto = Int32.TryParse(ddlAgeTo.SelectedValue, out to);

    result = result.AsQueryable().Where(p => p.Age >= from);
}

这里我有一个例外：

LINQ to Entities不支持指定的类型成员Age。
仅支持初始化，实体成员和实体导航属性
。

The specified type member "Age" is not supported in LINQ to Entities. Only initializers, entity members, and entity navigation properties are supported.

其中年龄不在数据库中这是我在clsProfileDate类中创建的属性，用于从DOB计算Age。任何解决方案？

Where Age is not in database it is property I created in clsProfileDate class to calculate Age from DOB. Any solution to this?

推荐答案

您不能使用未映射到中的数据库列的属性其中表达式。您必须基于映射属性构建表达式，如：

You cannot use properties that are not mapped to a database column in a Where expression. You must build the expression based on mapped properties, like:

var date = DateTime.Now.AddYears(-from);
result = result.Where(p => date >= p.DOB);
// you don't need `AsQueryable()` here because result is an `IQueryable` anyway

为了替代您未映射的年龄属性，您可以将此表达式解压缩成静态方法，如下所示：

As a replacement for your not mapped Age property you can extract this expression into a static method like so:

public class clsProfileDate
{
    // ...
    public DateTime DOB { get; set; } // property mapped to DB table column

    public static Expression<Func<clsProfileDate, bool>> IsOlderThan(int age)
    {
        var date = DateTime.Now.AddYears(-age);
        return p => date >= p.DOB;
    }
}

然后以这种方式使用：

result = result.Where(clsProfileDate.IsOlderThan(from));

这篇关于LINQ to Entities不支持指定的类型成员。只支持初始化器，实体成员和实体导航属性的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！