public void ExpTest()//返回所指定浮点表达式的指数值。
{
using (var edm = new NorthwindEntities())
{
var cust1 = from e in edm.Order_Details
select SqlFunctions.Exp(1M);
//EXP(1) AS [C1]
cust1.TraceSql();
Console.WriteLine(cust1.First());//2.71828182845905
}
}
private IQueryable <SuggestionValue> RetrieveSuggestions(ApplicationUser user)
{
return(
from sg in db.Suggestions
join us in db.UserSuggestions.Include("Status")
on sg.Id equals us.SuggestionId into us_sg
from j in us_sg.DefaultIfEmpty()
where
(
(
j.Status != SuggestionStatus.Completed &&
j.Status != SuggestionStatus.NotToday &&
j.Status != SuggestionStatus.NeverAsk
)
||
(
j.Status == SuggestionStatus.NotToday &&
SqlFunctions.DateDiff("day", j.DTAdded, SqlFunctions.GetDate()) > 1
)
&&
j.UserId == user.Id
)
select new SuggestionValue
{
Suggestion = sg,
Value = SqlFunctions.Exp(
(
(
from q in
(
sg.Suggestions.Select(q => q.Question)
)
join uq in db.UserQuestions on q.Id equals uq.QuestionId
where uq.UserId == user.Id
select uq.Response
)
.DefaultIfEmpty()
)
.Select(i => SqlFunctions.Log(i + 0.000001))
.DefaultIfEmpty()
.Sum()
),
Status = j.Status
}
);
}
// GET: api/Stories/rank/20
public IQueryable <StorySearchVM> GetStoriesByRank(int top)
{
IQueryable <Story> stories = from s in db.Stories
where s.StoryStatus == 1
orderby SqlFunctions.Exp(s.RateCount == 0? 0 : (double)s.Score / s.RateCount) descending
select s;
List <StorySearchVM> storyVMs = new List <StorySearchVM>();
StorySearchVM storySearchVM;
if (top > stories.Count())
{
top = stories.Count();
}
foreach (var story in stories.Take(top))
{
storySearchVM = new StorySearchVM(story);
storyVMs.Add(storySearchVM);
}
return(storyVMs.AsQueryable());
}
// GET: api/Reviews/rank/20
public IQueryable <ReviewVM> GetReviewsByRank(int top)
{
IQueryable <Review> reviews = from r in db.Reviews
where r.ReviewStatus == 1
orderby SqlFunctions.Exp(r.RateCount == 0? 0 : (double)(r.Score / r.RateCount)) descending
select r;
List <ReviewVM> reviewVMs = new List <ReviewVM>();
ReviewVM reviewVM;
if (top > reviews.Count())
{
top = reviews.Count();
}
foreach (var review in reviews.Take(top))
{
reviewVM = new ReviewVM(review);
reviewVMs.Add(reviewVM);
}
return(reviewVMs.AsQueryable());
}
