Linq在select {}中按聚合顺序排序

Question

这是我正在研究的一个:

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)

            } ;

我想按选择投影中的一个或多个字段排序.

Answer 1

最简单的更改可能是使用查询延续:

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;

这主要是相当于用"让",说实话-真正的区别是,让引入了一个新的范围变量,而查询持续有效地启动一系列变量的新天地-你不能指代grp位中后,into selection例如.

值得注意的是,这与使用两个语句完全相同:

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;