在linq查询asp.net中将字符串转换为十进制

我正在尝试使用实体查询从我的数据库表中获取一些数据的总和

i am trying to get the sum of some data from my database table using Entity Query

public List<total> gettotal(int apid)
    {
        var query = (from a in DB.TblApplicantInstallments
                     where
                         a.ApplicantId == apid
                     group a by a.ApplicantId into g
                     select new total()
                         {
                             paidtotal = g.Where(x => x.Status == "Paid").Sum(x =>decimal.Parse(x.InstallmentDueAmount)),
                            unpaidtoal = g.Where(x => x.Status == "Not Paid").Sum(x => (decimal)x.InstallmentDueAmount)

                         }).ToList();
        List<total> list = query.ToList();
        return list;
           }
}
public class total
{
    public decimal? paidtotal { get; set; }
    public decimal? unpaidtoal { get; set; }
}

但我收到以下错误：

LINQ to Entities无法识别方法' System.Decimal Parse（System.String）

请告诉我我的代码有什么问题？

提前谢谢

but i am getting the following error:
LINQ to Entities does not recognize the method 'System.Decimal Parse(System.String)
please tell me what is wrong with my code?
Thanks in advance