Linq order by aggregate in the select { }
Here is one I am working on:
var fStep =
from insp in sq.Inspections
where insp.TestTimeStamp > dStartTime && insp.TestTimeStamp < dEndTime
&& insp.Model == "EP" && insp.TestResults != "P"
group insp by new { insp.TestResults, insp.FailStep } into grp
select new
{
FailedCount = (grp.Key.TestResults == "F" ? grp.Count() : 0),
CancelCount = (grp.Key.TestResults == "C" ? grp.Count() : 0),
grp.Key.TestResults,
grp.Key.FailStep,
PercentFailed = Convert.ToDecimal(1.0 * grp.Count() /tcount*100)
} ;
I would l开发者_开发知识库ike to orderby one or more of the fields in the select projection.
The simplest change is probably to use a query continuation:
var fStep =
from insp in sq.Inspections
where insp.TestTimeStamp > dStartTime && insp.TestTimeStamp < dEndTime
&& insp.Model == "EP" && insp.TestResults != "P"
group insp by new { insp.TestResults, insp.FailStep } into grp
select new
{
FailedCount = (grp.Key.TestResults == "F" ? grp.Count() : 0),
CancelCount = (grp.Key.TestResults == "C" ? grp.Count() : 0),
grp.Key.TestResults,
grp.Key.FailStep,
PercentFailed = Convert.ToDecimal(1.0 * grp.Count() /tcount*100)
} into selection
orderby selection.FailedCount, selection.CancelCount
select selection;
That's mostly equivalent to using "let", to be honest - the real difference is that let introduces a new range variable, whereas a query continuation effectively starts a new scope of range variables - you couldn't refer to grp
within the bit after into selection
for example.
It's worth noting that this is exactly the same as using two statements:
var unordered =
from insp in sq.Inspections
where insp.TestTimeStamp > dStartTime && insp.TestTimeStamp < dEndTime
&& insp.Model == "EP" && insp.TestResults != "P"
group insp by new { insp.TestResults, insp.FailStep } into grp
select new
{
FailedCount = (grp.Key.TestResults == "F" ? grp.Count() : 0),
CancelCount = (grp.Key.TestResults == "C" ? grp.Count() : 0),
grp.Key.TestResults,
grp.Key.FailStep,
PercentFailed = Convert.ToDecimal(1.0 * grp.Count() /tcount*100)
};
var fStep = from selection in unordered
orderby selection.FailedCount, selection.CancelCount
select selection;
wrap the whole query in parentheses and
.OrderBy(x => x.FailedCount).ThenBy(x => x.CancelCount);
You can move the select value to a let assignment and then build an order by after that.
var fStep =
from insp in sq.Inspections
where insp.TestTimeStamp > dStartTime && insp.TestTimeStamp < dEndTime
&& insp.Model == "EP" && insp.TestResults != "P"
group insp by new { insp.TestResults, insp.FailStep } into grp
let newInsp = new
{
FailedCount = (grp.Key.TestResults == "F" ? grp.Count() : 0),
CancelCount = (grp.Key.TestResults == "C" ? grp.Count() : 0),
grp.Key.TestResults,
grp.Key.FailStep,
PercentFailed = Convert.ToDecimal(1.0 * grp.Count() / tcount * 100)
}
orderby newInsp.FailedCount, newInsp.CancelCount
// or this ...
//orderby newInsp.FailedCount
//orderby newInsp.CancelCount
select newInsp;
;
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