我有一个查询，它处理从各种表中提取的大约 500 条记录，分组然后汇总（如果这是一个词）到工作报告中。一切正常，但运行此报告大约需要 30 秒，而且我收到了用户的投诉。
有问题的程序是这样的：
public static List<LabourEfficiencies> GetLabourEfficienciesByTimeSheet(DateTime dateFrom, DateTime dateTo)
{
CS3Entities ctx = new CS3Entities();
//get all relevant timesheetline items
var tsItems = from ti in ctx.TimeSheetItems
where ti.TimeSheetHeader.Date >= dateFrom && ti.TimeSheetHeader.Date <= dateTo && ti.TimeSheetHeader.TimeSheetCategory != "NON-PROD"
select new TimesheetLine
{
TimesheetNo = ti.TimeSheetNo,
HoursProduced = ti.HoursProduced,
HoursProducedNet = ti.HoursProducedNet,
ItemID = ti.ItemID,
ProcessID = ti.ProcessID,
ProcessDuration = ti.ProcessDuration,
DowntimeHours = 0M
};
//get all relevant downtimeline items
var tsDownT = from dt in ctx.DowntimeItems
where dt.TimeSheetHeader.Date >= dateFrom && dt.TimeSheetHeader.Date <= dateTo && dt.TimeSheetHeader.TimeSheetCategory != "NON-PROD"
select new TimesheetLine
{
TimesheetNo = dt.TimeSheetNo,
HoursProduced = 0M,
HoursProducedNet = 0M,
ItemID = "",
ProcessID = "",
ProcessDuration = 0M,
DowntimeHours = dt.DowntimeHours
};
//combine them into single table
var tsCombi = tsItems.Concat(tsDownT);
var flatQuery = (from c in tsCombi
join th in ctx.TimeSheetHeaders on c.TimesheetNo equals th.TimeSheetNo
select new
{
th.TimeSheetNo,
th.EmployeeNo,
th.TimeSheetCategory,
th.Date,
c.HoursProduced,
c.ProcessDuration,
th.HoursWorked,
c.HoursProducedNet,
c.DowntimeHours,
c.ItemID
});
//add employee details & group by timesheet no (1 line per timesheet no)
//NB. FnTlHrs checks whether there are any indirect hrs & deducts them if there are
var query = flatQuery.GroupBy(f => f.TimeSheetNo).Select(g => new LabourEfficiencies
{
Eno = g.FirstOrDefault().EmployeeNo,
Dept =g.FirstOrDefault().TimeSheetCategory,
Date = g.FirstOrDefault().Date,
FnGrHrs =g.Where(w =>w.TimeSheetCategory == "FN" &&!w.ItemID.StartsWith("090")).Sum(h => h.HoursProduced),
FnTlHrs =g.Where(w =>w.ItemID.StartsWith("090")).Sum(h => h.ProcessDuration) >0? (g.FirstOrDefault(w =>w.TimeSheetCategory =="FN").HoursWorked) -(g.Where(w =>w.ItemID.StartsWith("090")).Sum(h =>h.ProcessDuration)): g.FirstOrDefault(w =>w.TimeSheetCategory =="FN").HoursWorked,
RmGrHrs =g.Where(w =>w.TimeSheetCategory == "RM").Sum(h => h.HoursProduced),RmGrHrsNet =g.Where(w =>w.TimeSheetCategory == "RM").Sum(h => h.HoursProducedNet),
RmTlHrs =g.FirstOrDefault(w =>w.TimeSheetCategory == "RM").HoursWorked,
MpGrHrs =g.Where(w =>w.TimeSheetCategory =="MATPREP").Sum(h => h.HoursProduced),
MpTlHrs =g.FirstOrDefault(w =>w.TimeSheetCategory =="MATPREP").HoursWorked,
DtHrs = g.Sum(s => s.DowntimeHours),
Indirect =g.Where(w =>w.ItemID.StartsWith("090")).Sum(h => h.ProcessDuration)
});
return query.ToList();
}
前几位只是收集数据，最后一个查询是过程的“肉”，需要时间。
我相当肯定我做了一些可怕的事情，因为它吐出的 SQL 很糟糕，但对于我的生活，我看不到如何改进它。
任何提示都非常感谢。
戈登