CODEWITHSUNDEEP
c#linq
Animesh D
Animesh D

Reputation: 5002

How do I get month names from this Linq group by query?

I use this query in LINQ to get grouped data:

string fmt = "yyyyMM";
var pivotedMeanResults =
    meanDataResults
    .GroupBy(i => i.Description)
    .Select(g => new PivotedMeanData
    {
        Description = g.Key,
        Month3Value = g.Where(c => DateTime.ParseExact(c.CollectionPeriod, fmt, invariantCulture).Month == currentMonth - 3).FirstOrDefault().LabResultNo.ToString(),
        Month2Value = g.Where(c => DateTime.ParseExact(c.CollectionPeriod, fmt, invariantCulture).Month == currentMonth - 2).FirstOrDefault().LabResultNo.ToString(),
        Month1Value = g.Where(c => DateTime.ParseExact(c.CollectionPeriod, fmt, invariantCulture).Month == currentMonth - 1).FirstOrDefault().LabResultNo.ToString()
        Month3Name = ? //
        Month2Name = ? //
        Month1Name = ? //
    }).ToList();

Data is in this format:

Item    Collection_Period   Value
====    =================   =====
Item4       201308          19
Item3       201209          2.1
Item2       201307          345
Item1       201309          13.11
Item2       201308          34
Item4       201308          58.2
Item3       201209          2.4
Item2       201309          12.1
Item1       201209          12.3

I need to manipulate data into this format, which, I am getting as needed:

Item    Month3Name  Month2Name  Month1Name
=====   =========   =========   =========
Item1                           13.11
Item2   345         34          12.1
Item3   
Item4   19          58.2

but I want to know if it is possible to get the month names (Month1Name, Month2Name, Month3Name) based on how the equivalent month values are derived in the grouping?

PS: I know I can generate month names can be generated like this:

CultureInfo cInfo = new CultureInfo("en-US");
DateTimeFormatInfo english = cInfo.DateTimeFormat;
english.GetAbbreviatedMonthName(integer)

So I tried this

Month3Name = english.GetAbbreviatedMonthName
(g.Where(DateTime.ParseExact(c.CollectionPeriod, fmt, invariantCulture)
.Month == currentMonth - 3))

but I get the errors:

Argument 1: cannot convert from 'System.Collections.Generic.IEnumerable<Namespace.Type.MeanData>' to 'int'

The best overloaded method match for 'System.Globalization.DateTimeFormatInfo.GetAbbreviatedMonthName(int)' has some invalid arguments

Upvotes: 0

Views: 1800

Answers (2)

mehmet mecek
mehmet mecek

Reputation: 2685

Just format dates like below; It will return the month name of the date.

        string month = DateTime.Now.ToString("MMMM", new CultureInfo("en-US"));
        //or
        month = new DateTime(1, 3, 1).ToString("MMMM", new CultureInfo("en-US"));

Upvotes: 0

oerkelens
oerkelens

Reputation: 5161

You want the name of the current month -1, -2, -3.

Then why are you trying tho get the name of the month from a subset of your data??

Month3Name = english.GetAbbreviatedMonthName(currentMonth - 3)

seems a lot more likely to give yo a monthname?

And yes, you cannot subtract 2 from January and expect a valid month :)

Upvotes: 1

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