我有一个自定义方法,可以对一组数据执行一些计算:
private int GetPercentages(int OriginalValue, int TotalValue)
{
var newValue = (int)Math.Round(((decimal)OriginalValue / (decimal)TotalValue) * 100);
return newValue;
}
我需要能够在 LINQ to Entities 查询中运行此方法:
var data = from SurveyResponseModel in db.SurveyResponseModels
group SurveyResponseModel by SurveyResponseModel.MemberId into resultCount
select new ResultsViewModel()
{
MemberId = resultCount.Key,
PatientFollowUpResult = db.SurveyResponseModels.Count(r => r.PatientFollowUp),
PatientFollowUpResultPct = GetPercentages(db.SurveyResponseModels.Count(r => r.PatientFollowUp),totalResponsesResult),
ChangeCodingPracticeResult = db.SurveyResponseModels.Count(r => r.ChangeCodingPractice),
};
我需要在查询内的大约 20 行以上运行它,因此将其内联似乎不是一个很好的选择。我知道它需要转换为 SQL 语法,但是我还能做其他类似的事情吗?
您需要创建一个 lambda 表达式来计算百分比,如下所示:
Expression<Func<int, int, int>> calcPercentage =
(OriginalValue, TotalValue) => (int)Math.Round(((decimal)OriginalValue / (decimal)TotalValue) * 100);
并像这样使用它:
var data = from SurveyResponseModel in db.SurveyResponseModels.ToExpandable()
group SurveyResponseModel by SurveyResponseModel.MemberId into resultCount
select new ResultsViewModel()
{
MemberId = resultCount.Key,
PatientFollowUpResult = db.SurveyResponseModels.Count(r => r.PatientFollowUp),
PatientFollowUpResultPct = calcPercentage.Invoke(db.SurveyResponseModels.Count(r => r.PatientFollowUp), totalResponsesResult),
ChangeCodingPracticeResult = db.SurveyResponseModels.Count(r => r.ChangeCodingPractice),
};
有关在 LINQ 查询中调用函数的更多信息here http://tomasp.net/blog/linq-expand.aspx.
本文内容由网友自发贡献,版权归原作者所有,本站不承担相应法律责任。如您发现有涉嫌抄袭侵权的内容,请联系:hwhale#tublm.com(使用前将#替换为@)