Here is my XElement tree
XElement myShoppingList = new XElement("myShoppingList",
new XElement("Pasadena", new XAttribute("Vendor", "Tesla"),
new XElement("Car",
new XElement("model3",
new XElement("Black")))),
new XElement("LasVegas", new XAttribute("Vendor", "Tesla"),
new XElement("Car",
new XElement("modelY",
new XElement("White")))),
new XElement("Pasadena", new XAttribute("Vendor", "Apple"),
new XElement("Phone",
new XElement("model13",
new XElement("Black")))),
new XElement("Pasadena", new XAttribute("Vendor", "Apple"),
new XElement("Phone",
new XElement("model12",
new XElement("White")))));
I can't seems to get this working, first question - When searching for "Pasadena" I should be getting 3 repeats:
var query = myShoppingList.Elements().AsEnumerable()
.GroupBy(x => x.XPathSelectElement("Pasadena"))
.Where(g => g.Count() > 1)
.Select(y => new { Element = y.Key, Counter = y.Count() })
.ToList();
When searching for Tesla in LasVegas I'm expecting 1 repeat
var query = myShoppingList.Elements().AsEnumerable()
.GroupBy(x => x.XPathSelectElement("Pasadena[#Name='Tesla']"))
.Where(g => g.Count() > 1)
.Select(y => new { Element = y.Key, Counter = y.Count() })
.ToList();
And finally I want to search for "White" regardless of who makes the widget then display its maker. So I'm expecting 2 repeats:
var query = myShoppingList.Elements().AsEnumerable()
.GroupBy(x => x.XPathSelectElement("../../../White"))
.Where(g => g.Count() > 1)
.SelectMany(y => y})
.ToList();
I'm not able get this working what am I doing wrong?
I can't seems to get this working, first question - When searching for
"Pasadena" I should be getting 3 repeats:
Is this what you're trying to achieve? :
var query = myShoppingList.XPathSelectElements("Pasadena")
.GroupBy(x => x.Name)
.Select(y => new { Element = y.Key, Counter = y.Count() });
When searching for Tesla in LasVegas I'm expecting 1 repeat
You could try it this way.
var query = myShoppingList.XPathSelectElements("Pasadena")
.Where(x => x.Attributes().Any(x => x.Name == "Vendor" && x.Value == "Tesla"))
.GroupBy(x => x.Name)
.Select(y => new { Element = y.Key, Counter = y.Count() });
For this one i'm not sure if that's what you want to achieve
var query = myShoppingList.XPathSelectElements("//White")
.GroupBy(x => x.Name)
.Select(y => new { Element = y.Key, Counter = y.Count() });
Related
I want add a new column to find which is lasted record in group.
Can I write subquery in Select() method?
I have try this
var test = DailyPeriods.Where(x => x.BookingDate == "2016/12/30")
.Select(x =>
new
{
PERIOD_GROUP_ID = x.PeriodGroupID,
PERIOD_NAME = x.PeriodName,
New_Column = DailyPeriods
.Where(z => z.BookingDate == "2016/12/30")
.Select(a =>
new
{
PeriodGroupID = a.PeriodGroupID,
period_name = a.PeriodName
}
)
.GroupBy(b => b.period_name)
.Select(g => g.Last().PeriodGroupID)
.Contains(x.PeriodName)
})
But will occur this error
"column not in scope: A:2211708.C(BOOKING_DATE)"
Try this..
var lastRecords = periodList.GroupBy(l => l.PeriodName)
.Select(x => new { PeriodName = x.Key,
PeriodGroupId = x.OrderBy(l => l.PeriodGroupId).Last().PeriodGroupId});
var result = from period in periodList
from lastRec in lastRecords.Where(r => r.PeriodGroupId == period.PeriodGroupId
&& r.PeriodName == period.PeriodName)
.DefaultIfEmpty()
select new { period.PeriodGroupId,period.PeriodName, New_Column=lastRec==null?false:true };
Trying to get my head around Linq, and at the same time keep track of the time I log on in the morning, which should be the time I get into the office thereabouts.
My code so far is:
EventLog SecurityLog = new EventLog("Security");
var AccountLoggedOnEntries = SecurityLog.Entries.Cast<EventLogEntry>()
.Where(x => x.InstanceId == 4624)
.Select(x => new
{
DateGenerated = x.TimeGenerated.ToShortDateString()
,
TimeGenerated = x.TimeGenerated.ToShortTimeString()
,
x.Message
})
.ToList();
DgvLogSummary.DataSource = AccountLoggedOnEntries;
DgvLogSummary.AutoSizeColumnsMode = DataGridViewAutoSizeColumnsMode.DisplayedCells;
I want to filter the results so that I only have one entry for each day, which is the earliest time.
In SQL I would normally take the Message of the earliest entry and then group by all fields.
How do I perform a similar query in Linq?
In LINQ you would group by, sort each group, and pick the first item:
var AccountLoggedOnEntries = log.Entries.Cast<EventLogEntry>()
.Where(x => x.InstanceId == 4624)
.GroupBy(x => x.TimeGenerated.Date)
.Select(g => g.OrderBy(x => x.TimeGenerated).First())
.Select(x => new {
DateGenerated = x.TimeGenerated.ToShortDateString()
, TimeGenerated = x.TimeGenerated.ToShortTimeString()
, x.Message
})
.ToList();
You could GroupBy the date and then select the minimum time
var AccountLoggedOnEntries = log.Entries.Cast<EventLogEntry>()
.Where(x => x.InstanceId == 4624)
.GroupBy(x => x.TimeGenerated.Date)
.Select(x => new {
DateGenerated = x.Key
, TimeGenerated = x.Min(y => y.TimeGenerated).ToShortTimeString()
})
.ToList();
Getting the appropriate Message is a little more tricky. One easy option is to use x.First().Message in the above Select projection.
Try this :
var AccountLoggedOnEntries = log.Entries.Cast<EventLogEntry>()
.Where(x => x.InstanceId == 4624)
.GroupBy(x => x.TimeGenerated.Date)
.Select(days => days.OrderBy(time => time.TimeGenerated).FirstOrDefault())
.Select(x => new
{
DateGenerated = x.TimeGenerated.ToShortDateString()
,
TimeGenerated = x.TimeGenerated.ToShortTimeString()
,
x.Message
})
.ToList();
var fpslist = db.FPSinformations.Where(x => x.Godown_Code != null && x.Godown_Code == godownid).ToList();
var data1 = fpslist.GroupBy(x => x.Ration_Card_Type1)
.Select(x => new
{
CardType_Name = x.Key,
CardType_Count = x.Sum(y => y.Ration_Card_Count1)
}).ToList();
var data2 = fpslist.GroupBy(x => x.Ration_Card_Type2)
.Select(x => new
{
CardType_Name = x.Key,
CardType_Count = x.Sum(y => y.Ration_Card_Count2)
}).ToList();
var data3 = fpslist.GroupBy(x => x.Ration_Card_Type3)
.Select(x => new
{
CardType_Name = x.Key,
CardType_Count = x.Sum(y => y.Ration_Card_Count3)
}).ToList();
var data4 = fpslist.GroupBy(x => x.Ration_Card_Type4)
.Select(x => new
{
CardType_Name = x.Key,
CardType_Count = x.Sum(y => y.Ration_Card_Count4)
}).ToList();
var data5 = fpslist.GroupBy(x => x.Ration_Card_Type5)
.Select(x => new
{
CardType_Name = x.Key,
CardType_Count = x.Sum(y => y.Ration_Card_Count5)
}).ToList();
var GodownRCCount = data1.Where(x => x.CardType_Name != null).ToList();
var GodownRCCounts = GodownRCCount;
GodownRCCount = data2.Where(x => x.CardType_Name != null).ToList();
GodownRCCounts.AddRange(GodownRCCount);
GodownRCCount = data3.Where(x => x.CardType_Name != null).ToList();
GodownRCCounts.AddRange(GodownRCCount);
GodownRCCount = data4.Where(x => x.CardType_Name != null).ToList();
GodownRCCounts.AddRange(GodownRCCount);
GodownRCCount = data5.Where(x => x.CardType_Name != null).ToList();
GodownRCCounts.AddRange(GodownRCCount);
I have 10 Columns in My Database Like
Ration_Card_Type1
Ration_card_count1
Ration_Card_Type2
Ration_card_count2
Ration_Card_Type3
Ration_card_count3
Ration_Card_Type4
Ration_card_count4
Ration_Card_Type5
Ration_card_count5
Now What I want is to get the sum of Ration_Card_Counts and Its Type from its Type
Expected Output :
CardType_Name
CardType_Count
Well the above code works fine but I want to optimize it in max possible way as this will be inside a Loop and there are about 1.5 million records.
Thanks
Union should operate faster than AddRange!
you can try the following:
var data = (from g in fpslist.GroupBy(x => x.Ration_Card_Type1).Select(x => new
{
CardType_Name = x.Key,
CardType_Count = x.Sum(y => y.Ration_Card_Count1)
}).Union(
fpslist.GroupBy(x => x.Ration_Card_Type2).Select(x => new
{
CardType_Name = x.Key,
CardType_Count = x.Sum(y => y.Ration_Card_Count2)
})).Union(
fpslist.GroupBy(x => x.Ration_Card_Type3).Select(x => new
{
CardType_Name = x.Key,
CardType_Count = x.Sum(y => y.Ration_Card_Count3)
})).Union(
fpslist.GroupBy(x => x.Ration_Card_Type4).Select(x => new
{
CardType_Name = x.Key,
CardType_Count = x.Sum(y => y.Ration_Card_Count4)
})).Union(
fpslist.GroupBy(x => x.Ration_Card_Type5).Select(x => new
{
CardType_Name = x.Key,
CardType_Count = x.Sum(y => y.Ration_Card_Count5)
}))
select g).ToList();
In general from grouping I would go with Thomas!
Database grouping is far better for me, since you are fetching the data required aggregated and therefore the data transferred over the network if much less!
You can rewrite the same query using SQL and put some indexes(performance) :
SELECT Ration_Card_Type = Ration_Card_Type1, Ration_Card_Count = sum(Ration_card_count1)
FROM
FPSinformations
GROUP BY
Ration_Card_Type1
UNION
SELECT Ration_Card_Type = Ration_Card_Type2, Ration_Card_Count = sum(Ration_card_count2)
FROM
FPSinformations
GROUP BY
Ration_Card_Type2
UNION
SELECT Ration_Card_Type = Ration_Card_Type3, Ration_Card_Count = sum(Ration_card_count3)
FROM
FPSinformations
GROUP BY
Ration_Card_Type3
UNION
SELECT Ration_Card_Type = Ration_Card_Type4, Ration_Card_Count = sum(Ration_card_count4)
FROM
FPSinformations
GROUP BY
Ration_Card_Type4
UNION
SELECT Ration_Card_Type = Ration_Card_Type5, Ration_Card_Count = sum(Ration_card_count5)
FROM
FPSinformations
GROUP BY
Ration_Card_Type5
I am not sure but this query make me think about UNPIVOT maybe you can investigate in this direction too.
I want to compare two lists extracted from two different tables
var maListe = db.exclure.Where(w => w.type.Contains("Object class"))
.GroupBy(g => new {libelle = g.libelle,})
.Select(s => new {libellex = s.Key.libelle}).ToList();
var myList = db.Full.Where(c => c.date_reception > new DateTime(2015, 02, 02))
.Where (c => !maListe.Any(c2 => c2.libellex.Contains(c.mc_object_class)))
//.Where (p => p.mc_object_class.CompareTo("NULL")<0)
.GroupBy(f => new
{
object_class = f.mc_object_class,
})
.Select(g => new
{
object_classx = g.Key.object_class,
countx = g.Count()
})
.Take(10)
.OrderByDescending(o => o.countx)
.ToList();
I'm looking for elements that exist in myList and not in maListe, while running the code above I get the following error:
Unable to create a constant value of type 'Anonymous type'. Only
primitive types or enumeration types are supported in this context.'
You should materialize your collection, something like:
var maListe = db.exclure.Where(w => w.type.Contains("Object class"))
.GroupBy(g => new {libelle = g.libelle,})
.Select(s => new {libellex = s.Key.libelle}).ToList();
var myList = db.Full.Where(c => c.date_reception > new DateTime(2015, 02, 02))
.AsEnumerable() // database query ends here
.Where (c => !maListe.Any(c2 => c2.libellex.Contains(c.mc_object_class)))
//.Where (p => p.mc_object_class.CompareTo("NULL")<0)
.GroupBy(f => new
{
object_class = f.mc_object_class,
})
.Select(g => new
{
object_classx = g.Key.object_class,
countx = g.Count()
})
.Take(10)
.OrderByDescending(o => o.countx)
.ToList();
If you will have time, please, take a look to msdn
I'm trying to convert below LINQ query result into dictionary
var browser = (from tbf in context.tblFeedBacks
where tbf.email == dboard.userEmail
select tbf).GroupBy(l => l.browser)
.Select(g => new
{
browser = g.Key,
count = g.Select(l => l.browser).Distinct().Count()
});
It gives me a compilation error.
var browser = (from tbf in context.tblFeedBacks
where tbf.email == dboard.userEmail
select tbf).GroupBy(l => l.browser)
.Select(g => new
{
browser = g.Key,
count = g.Select(l => l.browser).Distinct().Count()
}).ToDictionary<string, double>(x => x.browser,y=>y.count);
Instance argument: cannot convert from
'System.Linq.IQueryable' to
'System.Linq.ParallelQuery'
got it working.
var browser = (from tbf in context.tblFeedBacks
where tbf.email == dboard.userEmail
select tbf).GroupBy(l => l.browser)
.Select(g => new
{
browser = g.Key,
count = g.Select(l => l.browser).Count()
}).ToDictionary(x => x.browser, x => x.count);