C# Linq到实体过滤掉默认参数

假设我有以下方法，其中需要填充insuredNumber，但其余三个参数可能包含以下默认值

方法签名：

然后，如何在结果Linq to Entites查询中忽略这些默认值？我尝试了以下方法，但返回的结果比预期的多，因为日期筛选不正确

查询：

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我想我可以将查询分解为子查询，检查默认值，但我想看看这是否可以在一个语句中完成。

您最好将其分解：

var query = ctx.Portal_SurveyRecommendations
    .Where(c => c.CustNum == insuredNumber);
if(surveyLocationNumber != -1)
    query = query.Where(l => l.LocationKey == surveyLocationNumber);
if(dateIssuedFilter != DateTime.MinValue)
    query = query.Where(di => di.DateRecIssued == null
                           || di.DateRecIssued.Value > dateIssuedFilter);
if(dateCompletedFilter != DateTime.MinValue)
    query = query.Where(dc => dc.DateRecComplete == null
                           || dc.DateRecComplete.Value > dateCompletedFilter);
var surveys = query.OrderBy(o => o.ReportKey).ThenBy(o => o.RecNumKey).ToList();

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我也这么想。谢谢你，马克。

surveyLocationNumber = "-1"
dateIssuedFilter = DateTime.MinValue
dateCompletedFilter = DateTime.MinValue

var surveys = ctx.Portal_SurveyRecommendations.
                Where(c => c.CustNum.Equals(insuredNumber)).
                Where(l => l.LocationKey.ToString().Equals(surveyLocationNumber)).
                Where(di => di.DateRecIssued.Value > dateIssuedFilter || di.DateRecIssued.Value == null).
                Where(dc => dc.DateRecComplete.Value > dateCompletedFilter || dc.DateRecComplete.Value == null).
                OrderBy(o => o.ReportKey).ThenBy(o => o.RecNumKey).ToList();

var query = ctx.Portal_SurveyRecommendations
    .Where(c => c.CustNum == insuredNumber);
if(surveyLocationNumber != -1)
    query = query.Where(l => l.LocationKey == surveyLocationNumber);
if(dateIssuedFilter != DateTime.MinValue)
    query = query.Where(di => di.DateRecIssued == null
                           || di.DateRecIssued.Value > dateIssuedFilter);
if(dateCompletedFilter != DateTime.MinValue)
    query = query.Where(dc => dc.DateRecComplete == null
                           || dc.DateRecComplete.Value > dateCompletedFilter);
var surveys = query.OrderBy(o => o.ReportKey).ThenBy(o => o.RecNumKey).ToList();