Linq选择行当月的日期

Question

我需要获取当月的数据。一直找不到可行的解决方案。

这是我的代码，它为我提供了我需要的数据，但我从一整个月前获取数据，而不是从我们所在的当月获取数据。

我用row > DateTime.Today.Addmonths(-1)两次选择了日期“限制”

有什么想法吗？

var userQuery = 
from timeEntry in TimeEntries
                                //this displays a month back, not current month TODO: change to current month.
where timeEntry.DateEntity > DateTime.Today.AddMonths(-1)
select new {
    UserName = timeEntry.User.FirstName + " " +timeEntry.User.LastName,
    HoursEntered = timeEntry.HoursEntered,       
    User = timeEntry.User
};

var localrows = userQuery.ToList();

var grouping = localrows.GroupBy(x => x.User);

var userList = grouping.Select(q => new {
    UserName = q.FirstOrDefault().UserName,
    Hours = q.Sum(hr => hr.HoursEntered),                 //AbsenceTypeID = holiday(1)                          // still takes from a whole month, instead of current month.
    Holiday = q.FirstOrDefault().User.Absences.Where(a => a.AbsenceTypeID == 1).Where(date => date.DateEntity > DateTime.Today.AddMonths(-1)).Count(),
});

编辑：

Keyur Patel 的回答有效，但不是最底层的。

所以我要感谢朱尔斯：

DateTime.Today.AddDays((DateTime.Today.Day -1) * -1)

Answer 1

试试这个：

DateTime today = DateTime.Today;
var userQuery = 
from timeEntry in TimeEntries
where timeEntry.DateEntity.Month == today.Month && timeEntry.DateEntity.Year == today.Year
select new {
    UserName = timeEntry.User.FirstName + " " +timeEntry.User.LastName,
    HoursEntered = timeEntry.HoursEntered,       
    User = timeEntry.User
};

添加了对 .Year 的检查，因为它可能与其他年份的月份匹配（如果有的话）。

编辑

假期部分：

var userList = grouping.Select(q => new {
    UserName = q.FirstOrDefault().UserName,
    Hours = q.Sum(hr => hr.HoursEntered),
    Holiday = q.FirstOrDefault().User.Absences.Where(a => a.AbsenceTypeID == 1 && a.DateEntity.Month == today.Month && a.DateEntity.Year == today.Year).Count(),
});

Answer 2

您可以像这样仅比较日期的月份部分：

timeEntry.DateEntity.Month == DateTime.Now.Month

Answer 3

您可以使用 DateTime 类的Month 和Year 属性，如下所示：

var userQuery = TimeEntries
  .Where (te => te.DateEntity.Month == DateTime.Today.Month && te.DateEntity.Year == DateTime.Today.Year)
  .Select(timeEntry => 
    new {
      UserName = timeEntry.User.FirstName + " " + timeEntry.User.LastName,
      HoursEntered = timeEntry.HoursEntered,       
      User = timeEntry.User
    }
  );

Answer 4

你可以试试这个： .Where(x => x.EntityDate > DateTime.Now.AddDays(-DateTime.Now.Day).Date);