I'm trying to count the Total amount of Weight in a certain column.
I've tried the following coding, but I only seem to get the first row's value and not the rest.
int QuoteId = (from x in db.Quotes where x.Id != null orderby x.Id descending select x.Id).Take(1).SingleOrDefault();
var item = db.QuoteItems.Where(x => x.QuoteId == QuoteId).First();
QuoteItemSectionGroup quoteItemList = new QuoteItemSectionGroup();
foreach (var quoteItem in db.QuoteItemSectionGroups.Where(x => x.QuoteItemId == item.Id).ToList())
{
var total = new QuoteItemSectionGroup
{
Weight = quoteItem.Weight
};
quoteItemList.Weight = total.Weight;
}
So my question is: How can I count the total amount of the Weight column in my table?
You obviously want to add the current number to the Weigth you already obtained, don´t you? Furtheremore you won´t need to create a new instance of QuoteItemSectionGroup only for the sake of setting its Weight-property temporarily.
foreach (var quoteItem in db.QuoteItemSectionGroups.Where(x => x.QuoteItemId == item.Id).ToList())
{
quoteItemList.Weight += quoteItem.Weight; // pay attention on the + before the equality-character
}
The += operator in x += 1 is simply a shortcut for x = x + 1.
Or even simpler using Linq Sum-method
var totalWeight = db.QuoteItemSectionGroups
.Where(x => x.QuoteItemId == item.Id)
.Sum(x => x.Weight);
EDIT: Furthermore you can simplify your code a bit so it finally becomes this:
var item = db.Quotes.Where(x => x.Id != null)
.OrderByDescending(x => x.Id)
.FirstOrDefault();
var totalWeight = db.QuoteItemSectionGroups
.Where(x => x.QuoteItemId == item.Id)
.Sum(x => x.Weight);
Related
var totalDistributed = db.Distributions
.Select(m => m.Product.ProductName == (string)productNameComboBox.SelectedItem).Any()
? db.Distributions.Sum(m => m.Piece) : 0;
var totalStock = db.StockIns
.Select(m => m.Product.ProductName == (string)productNameComboBox.SelectedItem)
.Any() ? db.StockIns.Sum(m => m.Piece) : 0;
Using this code, I get the sum of all values, but I want to get sum of specific values through productId using a linq query. productId comes from productNameComboBox.
You can try Where filter function instead of Select if Where filter function does not find any matches, Sum will return 0.
var totalDistributed = db.Distributions
.Where(m => m.Product.ProductName == (string)productNameComboBox.SelectedItem).Sum(m => m.Piece);
var totalStock = db.StockIns
.Where(m => m.Product.ProductName == (string)productNameComboBox.SelectedItem).Sum(m => m.Piece);
I wanna transform my code:
using (DatabaseDataContext contestoDB = new DatabaseDataContext())
{
contestoDB.ObjectTrackingEnabled = false;
DateTime dataSelezionata = DateTime.Parse(data);
var elencoOre = (from db in contestoDB.Eventi
where db.DataPrenotazione.Date == dataSelezionata.Date select db);
foreach (var o in elencoOre)
oreOccupate += o.OrePreviste;
}
In this similar function for obtain sum of field with where :D :
var sum = contestoDB.Eventi.Sum(x => x.OrePreviste);
sum must be a int value...
Thanks
M.W.
Please see below:
var sum = contestoDB.Eventi
.Where(w => w.DataPrenotazione.Date == dataSelezionata.Date)
.Sum(x => x.OrePreviste);
You could just make a projection and take the sum of the projected values.
var sum = (from db in contestoDB.Eventi
where db.DataPrenotazione.Date == dataSelezionata.Date
select db.OrePreviste).Sum();
or equivalently try this:
var sum = contestoDB.Eventi
.Where(evt => evt.DataPrenotazione.Date == dataSelezionata.Date)
.Sum(evt => evt.OrePreviste);
I have a list of strings which contain X in them. I want to select list(s) with the minimum count of X in them. For example:
CountMin("AXBXX", "AAX") will return AAX.
How can I write this qith LINQ in a concise way ?
public static string CountMin(IList<string> inputList)
{
if (inputList == null || !inputList.Any()) return null;
var result = inputList.Select(s => new
{
Item = s,
Count => s.Count(ch => ch == 'X')
})
.OrderBy(item => item.Count).First().Item;
}
Snippet assumes that all elements on list are different to null. If you need it, it could be easily improved.
You can also omit temporary class:
inputList.OrderBy(s => s.Count(c => c == 'X')).First();
string[] list = {"AXBXX", "AAX", "AXX"};
string result = (from word in list
select new { word, wordLen = (word.Length - (word.Replace("X", "")).Length) })
.OrderBy(x => x.wordLen).First().word;
MessageBox.Show(result);
Here's an answer that will get you all of the minimum X strings from the list.
var listOfStrings = new List<string>()
{
"AXB",
"ABXXC",
"ABX",
};
var minimumXs =
listOfStrings
.GroupBy(x => x.Count(y => y == 'X'))
.OrderBy(x => x.Key)
.Take(1)
.SelectMany(x => x);
That gives me:
AXB
ABX
I'm trying to translate this sql statement
SELECT row, SUM(value) as VarSum, AVG(value) as VarAve, COUNT(value) as TotalCount
FROM MDNumeric
WHERE collectionid = 6 and varname in ('C3INEV1', 'C3INEVA2', 'C3INEVA3', 'C3INVA11', 'C3INVA17', 'C3INVA19')
GROUP BY row
into an EF 4 query using lambda expressions and am missing something.
I have:
sumvars = sv.staticvararraylist.Split(',');
var aavresult = _myIFR.MDNumerics
.Where(r => r.collectionid == _collid)
.Where(r => sumvars.Contains(r.varname))
.GroupBy(r1 =>r1.row)
.Select(rg =>
new
{
Row = rg.Key,
VarSum = rg.Sum(p => p.value),
VarAve = rg.Average(p => p.value),
TotalCount = rg.Count()
});
where the staticvararraylist has the string 'C3INEV1', 'C3INEVA2', 'C3INEVA3', 'C3INVA11', 'C3INVA17', 'C3INVA19' (without single quotes) and the _collid variable = 6.
While I'm getting the correct grouping, my sum, average, & count values aren't correct.
You didn't post your error message, but I suspect it's related to Contains. I've found that Any works just as well.
This should get you quite close:
var result =
from i in _myIFR.MDNumerics
where i.collectionid == _collid && sumvars.Any(v => i.varname == v)
group i by i.row into g
select new {
row = g.Key,
VarSum = g.Sum(p => p.value),
VarAve = g.Average(p => p.value),
TotalCount = g.Count()
};
Try this:
var aavresult = _myIFR.MDNumerics
.Where(r => r.collectionid == _collid && sumvars.Contains(r.varname))
.GroupBy(r1 =>r1.row,
(key,res) => new
{
Row = key,
VarSum = res.Sum(r1 => r1.value),
VarAve = res.Average(r1 => r1.value),
TotalCount = res.Count()
});
I'm optimizing a method with a number of Linq queries. So far the execution time is around 3 seconds and I'm trying to reduce it. There is quite a lot of operations and calculations happening in the method, but nothing too complex.
I will appreciate any suggections and ideas how the performance can be improved and code optimized.
The whole code of the method(Below I'll point where I have the biggest delay):
public ActionResult DataRead([DataSourceRequest] DataSourceRequest request)
{
CTX.Configuration.AutoDetectChangesEnabled = false;
var repoKomfortaktion = new KomfortaktionRepository();
var komfortaktionen = CTX.Komfortaktionen.ToList();
var result = new List<AqGeplantViewModel>();
var gruppen = new HashSet<Guid?>(komfortaktionen.Select(c => c.KomfortaktionsGruppeId).ToList());
var hochgeladeneKomplettabzuege = CTX.Komplettabzug.Where(c => gruppen.Contains(c.KomfortaktionsGruppeId)).GroupBy(c => new { c.BetriebId, c.KomfortaktionsGruppeId }).Select(x => new { data = x.Key }).ToList();
var teilnehmendeBetriebe = repoKomfortaktion.GetTeilnehmendeBetriebe(CTX, gruppen);
var hochgeladeneSperrlistenPlz = CTX.SperrlistePlz.Where(c => gruppen.Contains(c.KomfortaktionsGruppeId) && c.AktionsKuerzel != null)
.GroupBy(c => new { c.AktionsKuerzel, c.BetriebId, c.KomfortaktionsGruppeId }).Select(x => new { data = x.Key }).ToList();
var hochgeladeneSperrlistenKdnr = CTX.SperrlisteKdnr.Where(c => gruppen.Contains(c.KomfortaktionsGruppeId) && c.AktionsKuerzel != null)
.GroupBy(c => new { c.AktionsKuerzel, c.BetriebId, c.KomfortaktionsGruppeId }).Select(x => new { data = x.Key }).ToList();
var konfigsProAktion = CTX.Order.GroupBy(c => new { c.Vfnr, c.AktionsId }).Select(c => new { count = c.Count(), c.Key.AktionsId, data = c.Key }).ToList();
foreach (var komfortaktion in komfortaktionen)
{
var item = new AqGeplantViewModel();
var zentraleTeilnehmer = teilnehmendeBetriebe.Where(c => c.TeilnahmeStatus.Any(x => x.KomfortaktionId == komfortaktion.Id && x.AktionsTypeId == 1)).ToList();
var lokaleTeilnehmer = teilnehmendeBetriebe.Where(c => c.TeilnahmeStatus.Any(x => x.KomfortaktionId == komfortaktion.Id && x.AktionsTypeId == 2)).ToList();
var hochgeladeneSperrlistenGesamt =
hochgeladeneSperrlistenPlz.Count(c => c.data.AktionsKuerzel == komfortaktion.Kuerzel && c.data.KomfortaktionsGruppeId == komfortaktion.KomfortaktionsGruppeId) +
hochgeladeneSperrlistenKdnr.Count(c => c.data.AktionsKuerzel == komfortaktion.Kuerzel && c.data.KomfortaktionsGruppeId == komfortaktion.KomfortaktionsGruppeId);
item.KomfortaktionId = komfortaktion.KomfortaktionId;
item.KomfortaktionName = komfortaktion.Aktionsname;
item.Start = komfortaktion.KomfortaktionsGruppe.StartAdressQualifizierung.HasValue ? komfortaktion.KomfortaktionsGruppe.StartAdressQualifizierung.Value.ToString("dd.MM.yyyy") : string.Empty;
item.LokalAngemeldet = lokaleTeilnehmer.Count();
item.ZentralAngemeldet = zentraleTeilnehmer.Count();
var anzHochgelandenerKomplettabzuege = hochgeladeneKomplettabzuege.Count(c => zentraleTeilnehmer.Count(x => x.BetriebId == c.data.BetriebId) == 1) +
hochgeladeneKomplettabzuege.Count(c => lokaleTeilnehmer.Count(x => x.BetriebId == c.data.BetriebId) == 1);
item.KomplettabzugOffen = (zentraleTeilnehmer.Count() + lokaleTeilnehmer.Count()) - anzHochgelandenerKomplettabzuege;
item.SperrlisteOffen = (zentraleTeilnehmer.Count() + lokaleTeilnehmer.Count()) - hochgeladeneSperrlistenGesamt;
item.KonfigurationOffen = zentraleTeilnehmer.Count() - konfigsProAktion.Count(c => c.AktionsId == komfortaktion.KomfortaktionId && zentraleTeilnehmer.Any(x => x.Betrieb.Vfnr == c.data.Vfnr));
item.KomfortaktionsGruppeId = komfortaktion.KomfortaktionsGruppeId;
result.Add(item);
}
return Json(result.ToDataSourceResult(request));
}
The first half (before foreach) takes half a second which is okay. The biggest delay is inside foreach statement in the first iteration and in particular in these lines, execution of zentraleTeilnehmer takes 1.5 second for the first time.
var zentraleTeilnehmer = teilnehmendeBetriebe.Where(c => c.TeilnahmeStatus.Any(x => x.KomfortaktionId == komfortaktion.Id && x.AktionsTypeId == 1)).ToList();
var lokaleTeilnehmer = teilnehmendeBetriebe.Where(c => c.TeilnahmeStatus.Any(x => x.KomfortaktionId == komfortaktion.Id && x.AktionsTypeId == 2)).ToList();
TeilnehmendeBetriebe has over 800 lines, where TeilnahmeStatus property has normally around 4 items. So, maximum 800*4 iterations, which is not a huge number afterall...
Thus, I'm mostly interected in optimizing these lines, hoping to reduce execution time to half a second or so.
What I tried:
Rewrite Linq to foreach: didn't help, same time... probably not surprising, but was worth a try.
foreach (var tb in teilnehmendeBetriebe) //836 items
{
foreach (var ts in tb.TeilnahmeStatus) //3377 items
{
if (ts.KomfortaktionId == komfortaktion.Id && ts.AktionsTypeId == 1)
{
testResult.Add(tb);
break;
}
}
}
Selecting particular columns for teilnehmendeBetriebe with .Select(). Didn't help either.
Neither helped other small manipulations I tried.
What is interesting - while the first iteration of foreach can take up to 2 seconds, the second and further take just milisecons, so .net is capable of optimizing or reusing calculation data.
Any advice on what can be changed in order to improve performance is very welcome!
Edit:
TeilnahmeBetriebKomfortaktion.TeilnahmeStatus is loaded eagerly in the method GetTeilnehmendeBetriebe:
public List<TeilnahmeBetriebKomfortaktion> GetTeilnehmendeBetriebe(Connection ctx, HashSet<Guid?> gruppen)
{
return ctx.TeilnahmeBetriebKomfortaktion.Include(
c => c.TeilnahmeStatus).ToList();
}
Edit2:
The query which is sent when executing GetTeilnehmendeBetriebe:
SELECT
[Extent1].[Id] AS [Id],
[Extent1].[BetriebId] AS [BetriebId],
[Extent1].[MandantenId] AS [MandantenId],
[Extent1].[CreatedUser] AS [CreatedUser],
[Extent1].[UpdatedUser] AS [UpdatedUser],
[Extent1].[CreatedDate] AS [CreatedDate],
[Extent1].[UpdatedDate] AS [UpdatedDate],
[Extent1].[IsDeleted] AS [IsDeleted]
FROM [Semas].[TeilnahmeBetriebKomfortaktion] AS [Extent1]
WHERE [Extent1].[IsDeleted] <> cast(1 as bit)
My assumption is that TeilnahmeBetriebKomfortaktion.TeilnahmeStatus is a lazy loaded collection, resulting in the N + 1 problem. You should eagerly fetch that collection to improve your performance.
The following iterations of the foreach loop are fast, because after the first iteration those objects are no longer requested from the database server but are server from memory.