实体框架Linq Group by DateRange

Question

I have an application that records page visits and I need to be able to query by day by week and by month, sample output of a table query is as follows (each row represents a visit:

Visits result set

DateTimeLanding | PageViews
2016-05-12      | 2
2016-05-16      | 3
2016-05-16      | 8
2016-05-16      | 3
2016-05-17      | 7
2016-05-19      | 4
2016-05-28      | 6
2016-05-28      | 3
2016-05-30      | 1

If I want to query this result set for daily visits I do this:

var visitData = visits.GroupBy(v => v.DateLanding)
                            .OrderBy(g => g.Key)
                            .Select(g => new { From = g.Key, Count = g.Count() });

                    visitNodes.Num = visits.Count().ToString();
                    visitNodes.Nodes = visitData.Select(p => new ReferralTrafficNode()
                    {
                        MetricDateTimeFrom = p.From,
                        MetricDateTimeTo = p.From.AddDays(1),
                        Value = p.Count
                    }).ToList();

This works fine for daily visits as I can group date.

How can I group the result set into groups of 7 days to get weekly visit data? Essentially I need to be able to group by a date range

Answer 1

If you change your group by to this:

v => v.DateLanding.AddDays(-(int)v.DateLanding.DayOfWeek)

This should group by the Sunday of the week selected.