Hi I'm trying to filter my result with a date.
What I tried so far:
var lastYear = (DateTime.Now.Year) - 1;
var salesLastYear = _documentService.GetDocuments(
d => d.DocumentTypeId == saleDocumentId &&
d.EffectiveOnUtc.Contains(lastYear))
.Select(d => d.Id).ToList();
var salesLastYear = _documentService.GetDocuments(
d => d.DocumentTypeId == saleDocumentId &&
(d.EffectiveOnUtc.Year == lastYear))
.Select(d => d.Id).ToList();
Both gave no errors in visual studio, but did raise an exeption during execution.
Also tried to convert both the values to a string, but that also failed.
Working on the assumption that your EffectiveOnUtc is a DateTime, and you want to filter to records within the previous calendar year:
int lastYear = DateTime.Now.Year - 1;
DateTime minDate = new DateTime(lastYear, 1, 1);
DateTime maxDate = minDate.AddYears(1);
var salesLastYear = _documentService.GetDocuments(
d => d.DocumentTypeId == saleDocumentId
&& d.EffectiveOnUtc >= minDate
&& d.EffectiveOnUtc < maxDate)
Select(d => d.Id).ToList();
Related
The following query works, but I want to get the same result without using grp.Sum(). Can we do it?
from item in (await VehicleReplaceCostDataAsync())
group item by (item.type, item.size, item.ADA, item.eseq) into grp
orderby (grp.Key.eseq, grp.Key.size, grp.Key.ADA)
select new VehicleReplacementCost
{
type = grp.Key.type,
size = grp.Key.size,
ADA = grp.Key.ADA,
count = grp.Sum(x => x.count),
cost = grp.Sum(x => x.cost),
Fcount = grp.Sum(x => x.Fcount),
Fcost = grp.Sum(x => x.Fcost),
eseq = grp.Key.eseq,
}).ToList();
Perhaps by using .Aggregate()? [docs]
count = grp.Aggregate(0, (a, b) => a + b.count)
Thanks for the answer from Astrid. It looks like a good one, but I didn't test it. My colleague gave this solution instead by using yield:
var groups = costs
.GroupBy(type => (type.SystemId, type.Type, type.Size, type.ADA, type.Eseq))
.OrderBy(group => (group.Key.SystemId, group.Key.Eseq, group.Key.Size, group.Key.ADA));
foreach (var group in groups)
{
var result = new ProgramGuideVehicleCostRow
{
SystemId = group.Key.SystemId,
Type = group.Key.Type,
Size = group.Key.Size,
ADA = group.Key.ADA,
};
foreach (var row in group)
{
result.Cost += row.Cost;
result.Fcost += row.Fcost;
result.Count += row.Count;
result.Fcount += row.Fcount;
}
yield return result;
}
How do I go about counting missing values using linq. Basically I am counting occurrences within a particular month and I want the count to show as zero if there were no entries for that particular month.
However, currently if there are no entries for that month the array skips a month as shown at index 5 below. The reason I don't want this to happen is because I am plotting the results on a chart so the skipped dates are out of sync from index 5 onwards with the actual count.
Below is my linq query
var veterans = _db.Records
.Where(j => j.Requestor == "Veterans" && EF.Functions.DateDiffMonth(j.Request_Date, DateTime.Now) >= 0 && EF.Functions.DateDiffMonth(j.Request_Date, DateTime.Now) <= 24)
.GroupBy(g => new { g.Request_Date.Value.Year, g.Request_Date.Value.Month }).OrderBy(d => d.Key.Year).ThenBy(d => d.Key.Month)
.Select(group => new
{
Dates = group.Key,
Count = group.Count()
});
var veteransCount = veterans.Select(n => n.Count).ToArray();
You can create a helper function to generate the month+year enumeration you need:
public static IEnumerable<(int Year,int Month)> MonthsInYears(int fromYear, int fromMonth, int toYear, int toMonth) {
for (int year = fromYear; year <= toYear; ++year)
for (int month = (year == fromYear ? fromMonth : 1); month <= (year == toYear ? toMonth : 12); ++month)
yield return (year, month);
}
Then using this, you can create an enumeration of the period:
var veterans = _db.Records
.Where(j => j.Requestor == "Veterans" && EF.Functions.DateDiffMonth(j.Request_Date, DateTime.Now) >= 0 && EF.Functions.DateDiffMonth(j.Request_Date, DateTime.Now) <= 24)
.GroupBy(g => new { g.Request_Date.Value.Year, g.Request_Date.Value.Month }).OrderBy(d => d.Key.Year).ThenBy(d => d.Key.Month)
.Select(group => new {
YearMonth = group.Key,
Count = group.Count()
});
var minYearMonth = veterans.Select(v => v.YearMonth).First();
var maxYearMonth = veterans.Select(v => v.YearMonth).Last();
var monthsInYears = MonthsInYears(minYearMonth.Year, minYearMonth.Month, maxYearMonth.Year, maxYearMonth.Month);
Then you can GroupJoin (as a left join) to your database data:
var veteransCount = monthsInYears.GroupJoin(
veterans,
ym => new { ym.Year, ym.Month },
v => v.YearMonth,
(ym, sj) => sj.FirstOrDefault()?.Count ?? 0)
.ToArray();
Alternatively, since this is a specific case, you could create a Dictionary for your source data and lookup each enumeration value:
var veteransMap = veterans.ToDictionary(v => v.YearMonth, v => v.Count);
var veteransCount2 = monthsInYears.Select(ym => veteransMap.TryGetValue(new { ym.Year, ym.Month }, out var count) ? count : 0)
.ToArray();
NOTE: If you want the full beginning and ending years, you could just call the MonthsInYears method with 1 and 12 for the from and to months.
I have a datatable and want to select some records with LinQ in this format:
var result2 = from row in dt.AsEnumerable()
where row.Field<string>("Media").Equals(MediaTp, StringComparison.CurrentCultureIgnoreCase)
&& (String.Compare(row.Field<string>("StrDate"), dtStart.Year.ToString() +
(dtStart.Month < 10 ? '0' + dtStart.Month.ToString() : dtStart.Month.ToString()) +
(dtStart.Day < 10 ? '0' + dtStart.Day.ToString() : dtStart.Day.ToString())) >= 0
&& String.Compare(row.Field<string>("StrDate"), dtEnd.Year.ToString() +
(dtEnd.Month < 10 ? '0' + dtEnd.Month.ToString() : dtEnd.Month.ToString()) +
(dtEnd.Day < 10 ? '0' + dtEnd.Day.ToString() : dtEnd.Day.ToString())) <= 0)
group row by new { Year = row.Field<int>("Year"), Month = row.Field<int>("Month"), Day = row.Field<int>("Day") } into grp
orderby grp.Key.Year, grp.Key.Month, grp.Key.Day
select new
{
CurrentDate = grp.Key.Year + "/" + grp.Key.Month + "/" + grp.Key.Day,
DayOffset = (new DateTime(grp.Key.Year, grp.Key.Month, grp.Key.Day)).Subtract(dtStart).Days,
Count = grp.Sum(r => r.Field<int>("Count"))
};
and in this code, I try to iterate it with the following code:
foreach (var row in result2)
{
//... row.DayOffset.ToString() + ....
}
this issue occurred :
Object reference not set to an instance of an object.
I think it happens when there's no record with above criteria.
I tried to change it to enumerator like this , and use MoveNext() to check the data is on that or not:
result2.GetEnumerator();
if (enumerator2.MoveNext()) {//--}
but still the same error.
whats the problem?
I guess in one or more rows Media is null.
You then call Equals on null, which results in a NullReferenceException.
You could add a null check:
var result2 = from row in dt.AsEnumerable()
where row.Field<string>("Media") != null
&& row.Field<string>("Media").Equals(MediaTp, StringComparison.CurrentCultureIgnoreCase)
...
or use a surrogate value like:
var result2 = from row in dt.AsEnumerable()
let media = row.Field<string>("Media") ?? String.Empty
where media.Equals(MediaTp, StringComparison.CurrentCultureIgnoreCase)
...
(note that the last approach is slightly different)
In my code below, is there any way I can use the results in the object 'WasteRecordsExcluded' to join with searchResults, essentially excluding the WasteId's I don't want.
If I debug to the last line I get the error :
base {System.SystemException} = {"The query contains references to items defined on a different data context."}
Or if joining is impossible then i could change bHazardous from TRUE to FALSE and FALSE to TRUE and do some kind of 'NOT IN' comparison.
Going bananas with this one, anyone help? Kind Regards :
var allWaste = _securityRepository.FindAllWaste(userId, SystemType.W);
var allWasteIndicatorItems = _securityRepository.FindAllWasteIndicatorItems();
// First get all WASTE RECORDS
var searchResults = (from s in allWaste
join x in allWasteIndicatorItems on s.WasteId equals x.WasteId
where (s.Description.Contains(searchText)
&& s.Site.SiteDescription.EndsWith(searchTextSite)
&& (s.CollectedDate >= startDate && s.CollectedDate <= endDate))
&& x.EWC.EndsWith(searchTextEWC)
select s).Distinct();
var results = searchResults;
if (hazardous != "-1")
{
// User has requested to filter on Hazardous or Non Hazardous only rather than Show All
var WasteRecordsExcluded = (from we in _db.WasteIndicatorItems
.Join(_db.WasteIndicators, wii => wii.WasteIndicatorId, wi => wi.WasteIndicatorId, (wii, wi) => new { wasteid = wii.WasteId, wasteindicatorid = wii.WasteIndicatorId, hazardtypeid = wi.HazardTypeId })
.Join(_db.HazardTypes, w => w.hazardtypeid, h => h.HazardTypeId, (w, h) => new { wasteid = w.wasteid, hazardous = h.Hazardous })
.GroupBy(g => new { g.wasteid, g.hazardous })
.Where(g => g.Key.hazardous == bHazardous && g.Count() >= 1)
select we);
// Now join the 2 object to eliminate all the keys that do not apply
results = results.Where(n => WasteRecordsExcluded.All(t2 => n.WasteId == t2.Key.wasteid));
}
return results;
Maybe something like this:
.....
var results = searchResults.ToList();
.....
.....
.Where(g => g.Key.hazardous == bHazardous && g.Count() >= 1)
select we).ToList();
.....
I'm trying to construct a Linq statement to be used from a client with the Sharepoint (2010) object model.
This is the problematic piece of code:
var result = news.Where(n => (bool)n["Online"]
&& ((DateTime)n["StartDate"] <= DateTime.Now && (DateTime)n["StopDate"] >= DateTime.Now));
if (currentUser.IsAgUser())
result = result.Where(n => (string)n["Role"] != "AG-ADMIN");
var filteredNews = sharepointContext.LoadQuery(result);
When the if parte is executed and so another Where is added to result, I get the followin error when LoadQuerying it.
The query expression 'value(Microsoft.SharePoint.Client.ListItemCollection).Where(n => (Convert(n.get_Item("Online")) AndAlso ((Convert(n.get_Item("StartDate")) <= DateTime.Now) AndAlso (Convert(n.get_Item("StopDate")) >= DateTime.Now)))).Where(n => (Convert(n.get_Item("Role")) != "AG-ADMIN"))' is not supported.
Where is the error coming from? Thanks
It seems like SharePoint doesn't support several wheres.
Cheap solution:
var result = currentUser.IsAgUser()
? news.Where(n => (bool)n["Online"]
&& ((DateTime)n["StartDate"] <= DateTime.Now && (DateTime)n["StopDate"] >= DateTime.Now) && (string)n["Role"] != "AG-ADMIN")
: news.Where(n => (bool)n["Online"]
&& ((DateTime)n["StartDate"] <= DateTime.Now && (DateTime)n["StopDate"] >= DateTime.Now));
var filteredNews = sharepointContext.LoadQuery(result);