C# 如何比较Linq中日期字段的年份?
我使用以下代码比较两个日期的年份:C# 如何比较Linq中日期字段的年份?,c#,asp.net,linq,asp.net-mvc-4,C#,Asp.net,Linq,Asp.net Mvc 4,我使用以下代码比较两个日期的年份: public string GetResultWbyYears() { using (var context = new DbEntity()) { int yeat = DateTime.Now.Year; var holidays = (from rl in context.HolidayMasters where
public string GetResultWbyYears()
{
using (var context = new DbEntity())
{
int yeat = DateTime.Now.Year;
var holidays = (from rl in context.HolidayMasters
where rl.Isactive == true && rl.Isdelete == false //&& rl.HolidayDate.Year == yeat
orderby rl.HolidayDate ascending
select new HolidayEntity
{
HolidayDesc = rl.HolidayDesc,
HolidayDate = rl.HolidayDate,
HolidayId = rl.HolidayId
}).ToList().AsEnumerable().Select(x => new HolidayEntity()
{
HolidayDesc = x.HolidayDesc,
HolidayDate = x.HolidayDate,
Isactive = x.Isactive,
Isdelete = x.Isdelete,
HolidayId = x.HolidayId,
Zones = GetZonesWithSelectedForHolidays(x.HolidayId)
}).ToList();
holidays = holidays.Where(n => n.HolidayDate.Year == yeat).ToList();
}
不明白为什么上述方法不起作用。。请帮助我怎样才能在一年内得到结果
我在谷歌上搜索过,发现一些文章和我上面做的一样,但这对我不起作用。这就是为什么我发布了这个问题 选择
IEnumerable
,然后将其转换为列表
,丢失Isactive
和Isdelete
默认值,然后再次选择IEnumerable
。其实这是没有必要的 您的LINQ可以看起来更漂亮:
public string GetResultWbyYears()
{
int year = DateTime.Now.Year;
using (var context = new DbEntity())
{
var result = context.HolidayMasters
.Where(hm => hm.Isactive && !hm.Isdelete && hm.HolidayDate.Year == year)
.OrderBy(hm => hm.HolidayDate)
.ToList();
foreach (var item in result)
item.Zones = GetZonesWithSelectedForHolidays(item.HolidayId);
}
}
或者以另一种方式:
public string GetResultWbyYears()
{
int year = DateTime.Now.Year;
using (var context = new DbEntity())
{
var result = (from hm in dbSet
where hm.Isactive && !hm.Isdelete && hm.HolidayDate.Year == 2015
orderby hm.HolidayDate ascending
select hm).ToList();
foreach (var item in result)
item.Zones = GetZonesWithSelectedForHolidays(item.HolidayId);
}
}
我假设您的
context.HolidayMasters
属于dbset类型,您为什么选择IEnumerable
,然后将其转换为List
,然后再次选择IEnumerable
?您的Isactive
和Isdelete
将始终是默认值(false
,我猜)。您有任何错误吗?您的代码看起来不错me@kienct89没有错误。但始终返回0条记录。即使在DB中,我们也有电流的记录ear@YeldarKurmangaliyev,这两个值可为空,因此没有默认值。其次,第二个IEnumerable是为每个holiday@RamSingh此外,您的方法返回List
,而方法的返回类型为string
。
public string GetResultWbyYears()
{
int year = DateTime.Now.Year;
using (var context = new DbEntity())
{
var result = (from hm in dbSet
where hm.Isactive && !hm.Isdelete && hm.HolidayDate.Year == 2015
orderby hm.HolidayDate ascending
select new HolidayEntity {
HolidayDesc = x.HolidayDesc,
HolidayDate = x.HolidayDate,
Isactive = x.Isactive,
Isdelete = x.Isdelete,
HolidayId = x.HolidayId,
Zones = GetZonesWithSelectedForHolidays(x.HolidayId)
}).ToList();
}
}