按总和Linq分组到C＃中的SQL

首先定义一个类来保存结果：

public class GroupedRow{  public string UserDescription {get;set;}  public string ProjectDescription {get;set;}  public double SumOfHoursBetweenToAndFromDate {get;set;}}

由于您已经应用了过滤，因此剩下要做的就是分组。

List<GroupedRow> result =(  from row in source  group row by new { row.UserDescription, row.ProjectDescription } into g  select new GroupedRow()  {    UserDescription = g.Key.UserDescription,    ProjectDescription = g.Key.ProjectDescription,    SumOfHoursBetweenToAndFromDate = g.Sum(x => x.Hours)  }).ToList();

（或其他语法）

List<GroupedRow> result = source  .GroupBy(row => new {row.UserDescription, row.ProjectDescription })  .Select(g => new GroupedRow()  {    UserDescription = g.Key.UserDescription,    ProjectDescription = g.Key.ProjectDescription,    SumOfHoursBetweenToAndFromDate = g.Sum(x => x.Hours)  })  .ToList();