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我有查詢下面,如圖碼組學生通過class
,group
,enrollment
導致數據嵌套組的LINQ實體框架
public List<PassingRatioDTO> GetStudentPassingRatio()
{
using(SMSEntities em=new SMSEntities())
{
try
{
List<PassingRatioDTO> result = (from results in em.ResultDetails
where results.ExamDate.Year == 2016
group results by new {results.Class_Id, results.Group_Id, results.EnrollmentId } into groupedRresult
select new PassingRatioDTO()
{
Percentage = (((groupedRresult.Where(s => s.Status == "Pass").Count()) * 100)/groupedRresult.Count()),
ClassName = groupedRresult.Where(s => s.Class_Id == s.ClassDetail.Class_Id).Max(s => s.ClassDetail.ClassName),
GroupName = groupedRresult.Where(s => s.Group_Id == s.GroupDetail.Group_Id).Max(s => s.GroupDetail.Group_Name),
Year = groupedRresult.Max(s => s.ExamDate.Year),
}
).ToList();
return result;
}
catch(Exception ex)
{
return null;
}
}
我再次希望將這個查詢結果和計算比例(其中是一個派生列),其中百分比大於40 ..
@AlperTungaArslan如何計算百分比計數(百分比)。 想知道有多少學生通過了班級 –
因此,您需要列表中的PassingRatioDTO對象的數量,其中Percentage> 40? – grek40
@ grek40是的這樣的事情,想知道類「ABC」有多少學生有> 40 –