C# LInq到实体选择新计数,其中
我已经创建了有史以来最复杂的linq查询,但仍然没有完全满足我的需要。从这个查询中,我需要知道EventStudents表中有多少相关的学生具有C# LInq到实体选择新计数,其中,c#,linq,entity-framework-5,C#,Linq,Entity Framework 5,我已经创建了有史以来最复杂的linq查询,但仍然没有完全满足我的需要。从这个查询中,我需要知道EventStudents表中有多少相关的学生具有DateDeleted==null。因此,StudentCount=ev.EventStudents-where DateDeleted==null.Count()。 有人能帮忙吗 var inf = (from ev in db.Events where (ev.StartDate >= beginDate && e
DateDeleted==null
。因此,StudentCount=ev.EventStudents-where DateDeleted==null.Count()。
有人能帮忙吗
var inf = (from ev in db.Events
where (ev.StartDate >= beginDate && ev.StartDate <= endDate)
&& ev.DeletedDate == null
orderby ev.StartDate descending
select new
{
EventID = ev.EventID,
EventTitle = ev.Title,
EventDate = ev.StartDate,
StudentCount = ev.EventStudents.Count(),
CreatedUsername = ev.CreatedUsername
}).AsEnumerable().Select(x => new
{
EventID = x.EventID,
EventTitle = x.EventTitle,
EventDate = x.EventDate,
StudentCount = x.StudentCount,
CreatedUsername = x.CreatedUsername,
CreatedFullname = sortedUserDictionary.Where(u => u.Value == x.CreatedUsername)
.Select(f => f.Key)
.FirstOrDefault() ?? x.CreatedUsername
});
var inf=(来自以db.Events表示的ev)
其中(ev.StartDate>=beginDate和ev.StartDate new)
{
EventID=x.EventID,
EventTitle=x.EventTitle,
EventDate=x.EventDate,
StudentCount=x.StudentCount,
CreatedUsername=x.CreatedUsername,
CreatedFullname=sortedUserDictionary.Where(u=>u.Value==x.CreatedUsername)
.选择(f=>f.Key)
.FirstOrDefault()??x.CreatedUsername
});
将ev.EventStudents.Count()更改为ev.EventStudents.Count(es=>es.DateDeleted==null)