修改

Question

我目前有一个linq查询，它从我的视图中的日期输入中获取值。

var applications = from s in db.ElmahErrors
                   where s.TimeUtc >= startDate && s.TimeUtc < endDate
                   select s;

因此，此查询显示在输入中选择的那一天发生的每个错误。

许多错误是具有相同应用程序名称和类型的重复出现的错误。我想按应用程序名称和类型对这些错误进行分组，因此它只显示每个错误的一行。

我已经给了它一个去，但它似乎不喜欢它。

修改

var applications = from s in db.ElmahErrors
               where s.TimeUtc >= startDate && s.TimeUtc < endDate
               group s by new {s.Application, s.Type } into g
               select new ElmahError
               {
                   Application = g.Key,
                   Type = g.Key,
                   ErrorCount = g.Count()

               };

模型

[Table("ELMAH_Error")]
public class ElmahError
{
    [Key]
    public System.Guid ErrorId { get; set; }

    public System.String Application { get; set; }
    public System.String Host { get; set; }
    public System.String Type { get; set; }
    public System.String Source { get; set; }
    public System.String Message { get; set; }
    public System.String User { get; set; }
    public System.Int32 StatusCode { get; set; }
    public System.DateTime TimeUtc { get; set; }
    public System.Int32 Sequence { get; set; }
    public System.String AllXml { get; set; }

    public int ErrorCount { get; set; }
}

任何帮助都将不胜感激。

提前致谢。

Answer 1

我在这里猜你的字段/属性名称，但这应该有效：

var applications = from s in db.ElmahErrors
                   where s.TimeUtc >= startDate && s.TimeUtc < endDate
                   group by new { s.Application, s.Type } into grp
                   select grp;

Answer 2

您需要的只是group by条款： -

var ErrorsByapplications = from s in db.ElmahErrors
                   where s.TimeUtc >= startDate && s.TimeUtc < endDate
                   group s by new {s.ApplicationName, s.Type } into g
                   select new 
                     {
                        ApplicationName = g.Key,
                        Type = g.Key,
                        TotalErrors = g.Count()
                       ...and so on
                     };

<强>更新

如果您的ElmahError类已经拥有ApplicationName，Type等属性，那么您可以投影： -

group s by new {s.ApplicationName, s.Type } into g
select new ElmahError 
       {
           ApplicationName = g.Key,
           Type = g.Key,
           TotalErrors = g.Count() //If you have such property
           ErrorMessage = f.First().Errormessage //This will display only first 
                                          //error out of all (Consider checking for nulls)
        };

Answer 3

试试这个：

var ErrorsByapplications = from s in db.ElmahErrors
                           where s.TimeUtc >= startDate && s.TimeUtc < endDate
                           group s by new {s.Application, s.Type } into g
                           select new 
                           {
                              ApplicationName = g.Key,
                              Error = g.ToList()
                           };

将分组添加到LINQ查询

修改

模型

3 个答案: