Question

Inside a compiled LINQ query as a condition part, I was using Datetime.Now . It used to give me irrelevant results. I think it used to store same Datetime.Now value for few subsequent calls. To solve this issue I send Datetime.Now as a value parameter to the compiled query and it is working fine.

Old Code

     event.EventEnd >= Datetime.Now

New Code

     event.EventEnd >= currentTime

Where currentTime is a variable contains Datetime.Now value received outside from compiled query.

Please let me know if this is the default behavior of complied LINQ query or I was wrong somewhere

Platform : ASP.NET 4.0, MVC 2.0

Irrelevant results means , say we have one record with eVent.EventEnd value is 10-10-10 02:10 PM , if I run the query at 10-10-10 02:00 PM , we get that record in the result. If I run the query at 10-10-10 03:00 PM also we get that record in result. Which is wrong. But after I use the variable instead on DateTime.Now , it is working fine.

Compiled LINQ Query

public static Func<DataContext, CommonParams, string, DateTime, IQueryable<EventEntity>> GetEventsByOwnerID 
= CompiledQuery.Compile(
(DataContext context, CommonParams inputParams, string eventType, DateTime currentTime ) =>
   (from eVent in context.Events
    join categories in context.Categories on eVent.CategoryID equals categories.CategoryID
    where  !eVent.IsDeleted 
    && eVent.OwnerID == inputParams.UserID
    && (eventType == "ALL" ||
        (eventType == "CURRENT" && eVent.EventEnd >= currentTime) ||
        (eventType == "OLD" && eVent.EventEnd < currentTime))
    orderby eVent.PostedOn descending
    select new EventEntity()
    {
        EventID = eVent.EventID,
        CategoryID = eVent.CategoryID,
        Title = eVent.Title,
        Owner = eVent.OwnerName,
        EventStart = eVent.EventStart,
        EventEnd = eVent.EventEnd,
        Host = eVent.Host,
        Location = eVent.Location,
        Description = eVent.Description,
        Email = eVent.Email,
        URL = eVent.URL,
        Phone = eVent.Phone,
        CategoryName = categories.CategoryName,
        ProgramName = eVent.ProgramName,
        IsTelevised = eVent.IsTelevised,
        ChannelName = eVent.ChannelName,
        CityID = eVent.CityID,
        CountryID = eVent.CountryID,
        IsActive = eVent.IsActive,
        OwnerID = eVent.OwnerID,
        IsEndTimePartEmpty = eVent.IsEndTimePartEmpty,
        IsStartTimePartEmpty = eVent.IsStartTimePartEmpty,
        IsDeleted = eVent.IsDeleted,
        ThumbnailURL = eVent.ThumbnailURL,
        AttendeeCount = eVent.AttendeeCount,
        CommentsCount = eVent.CommentsCount
    })
);

Answer 1

I saw the same issue. I verified using SQL Profiler that it had cached the value of DateTime.Now.