从实例化的"System.Int32"类型到"System.Double"类型的指定强制转换无效 [英] The specified cast from a materialized 'System.Int32' type to the 'System.Double' type is not valid

问题描述

执行以下查询时，出现错误:

When executing the following query, I get the error:

从具体化的"System.Int32"类型到 "System.Double"类型无效.

The specified cast from a materialized 'System.Int32' type to the 'System.Double' type is not valid.

var data = ctx.tblTO
                   .Where(m => m.Id == Id)
                   .GroupBy(m => m.EmployeeId)
                   .Select(m => new
                   {
                       workDay = m.Sum(k => k.WorkDay),
                       onDutyDay = m.Sum(k => k.OnDutyDay),
                       holiDay = m.Sum(k => k.Holiday)
                   })
                   .FirstOrDefault();

WorkDay，OnDutyDay和Holiday的数据类型为double.这里没有Int32，为什么我会出现此错误?

The datatype of WorkDay, OnDutyDay and Holiday is double. There is no Int32 here, so why do I get this error?

如何解决此错误?

public class TO
{
    [Key]
    [DatabaseGenerated(DatabaseGeneratedOption.Identity)]
    public int Id { get; set; }           
    public int EmployeeId { get; set; }
    public double WorkDay { get; set; }
    public double OnDutyDay { get; set; }
    public double Holiday { get; set; }
}

推荐答案

我认为数据库表中各列的数据类型为Int32，但是您的数据模型具有double.您需要将数据模型的数据类型更改为int. materialized表示在数据库上运行查询时得到的类型.

I think the data type of the columns inside your database table is Int32 but your data model has double. You need to change the data types of your data models to int. By materialized it means the type it got when it ran the query on the database.

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