实体LINQ法的连锁查询

好吧，让说，下面是我所导入的实体模型我的数据库结构：实体LINQ法的连锁查询

Place 
---------------- 
Id bigint PK 
Name varchar(10) 

Time 
---------------- 
Id bigint PK 
PlaceId bigint FK_Place_Id 
StartTime datetime 
EndTime datetime 

DayOfWeek 
---------------- 
Id bigint PK 
Name varchar(10) 

TimeDayOfWeek 
---------------- 
TimeId bigint PK FK_Time_Id 
DayOfWeekId bigint PK FK_DayOfWeek_Id

在LINQ方法链我愿做类似下面的东西：

public List<Place> GetPlaces(SearchRequest request) 
     { 
      using(var c = new Context()) 
      { 
       var placereturn = c.Places.AsEnumerable(); 

       if (request.StartTime.HasValue) 
        placereturn = c.Places.Where(s => s.Time.Any(t => t.StartTime >= request.StartTime)); 
       if (request.EndTime.HasValue) 
        placereturn = c.Places.Where(s => s.Time.Any(t => t.EndTime >= request.EndTime)); 
       if (request.DayOfWeek.HasValue) 
        placereturn = c.Places.Where(s => s.Time.Any(t => t.DayOfWeeks.Any(z => z.Day = request.DayOfWeek))); 
       return placereturn; 
      } 
     }

除了星期几线以外的所有作品。

来源

2011-01-27 Cyberdrew

public List<Place> GetPlaces(SearchRequest request) 
     { 
      using (var c = new Context()) 
      { 
       var placereturn = c.Places.AsEnumerable(); 
       if (request.StartTime.HasValue) 
        placereturn = c.Places.Where(s => s.Time.Any(t => t.StartTime >= request.StartTime)); 
       if (request.EndTime.HasValue) 
        placereturn = c.Places.Where(s => s.Time.Any(t => t.EndTime >= request.EndTime)); 
       if (request.DayOfWeek.HasValue) 
        placereturn = c.Places.Where(s => s.Time.Any(t => t.DayOfWeeks.Any(z => z.Name == request.DayOfWeek.Value))); 
       return placereturn; 
      } 
     }

我发现，这个作品！

来源

2011-01-27 20:54:30 Cyberdrew

你已经接近我认为你是后：

Public List<Place> GetPlaces(SearchRequest request) 
    { 
     using(var c = new Context()) 
     { 
      var placereturn = c.Places; 

      if (request.StartTime.HasValue) 
       placereturn = placeretun.Where(???); //Any place that has a start time greater than or equal to the search start time 
      if (request.EndTime.HasValue) 
       placereturn = placeretun.Where(???);//Any place that has a end time less than or equal to the search end time 
      if (request.DayOfWeek.HasValue) 
       placereturn = placeretun.Where(???);//Any place where the day of week = the search day of week 
      return placereturn.ToList(); 
     } 
    }

你可以只保留追加到您的查询。直到实际使用它才会被评估。在这种情况下，将在返回时调用ToList时进行评估。

来源

2011-01-27 20:32:35 Geoff

这项工作？ placereturn = placereturn.Where（s => s.Time.Any（t => t.StartTime> = request.StartTime.Value））; – Cyberdrew 2011-01-27 20:37:47

我知道我忘了placereturn = placereturn。 DOH！我正在写在记事本中。 – Cyberdrew 2011-01-27 20:38:25

我想你所指的问号：

if (request.StartTime.HasValue) 
      placereturn.Where(r => r.StartTime >= DateTime.Now);

等等......

来源

2011-01-27 20:39:28

实体LINQ法的连锁查询

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