CODEWITHSUNDEEP
c#visual-studiofunc
Arijit Mukherjee
Arijit Mukherjee

Reputation: 3885

Does Not Contain Definition for GroupBy

public struct CardGrouping
    {
        public string Name { get; set; }
        public int Count { get; set; }
    }

    public List<CardGrouping> GetCardGrouping(IQueryable<Areas.RetailShop.Models.FPSinformation> queryable, Expression<Func<Areas.RetailShop.Models.FPSinformation, string>> groupingFunction)
    {
        return queryable.GroupBy(groupingFunction)
                .Where(x => x.Key != null)
                .Select(x => new CardGrouping
                {
                    Name = x.Key,
                    Count = x.Sum(groupingFunction)
                }).ToList();
    }

I'm trying to do something like this but getting an Error

IQueryable<FPSinformation> does not contain a definition for 'GroupBy' and the best extension method overload ParallelEnumerable.GroupBy<string, int>(ParallelQuery<string>, Func<string, int>) requires a receiver of type ParallelQuery<string>

What I'm doing wrong?

EDIT

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();

This is the actual code which I'm trying to optimise

Upvotes: 0

Views: 2565

Answers (2)

Ahmed Galal
Ahmed Galal

Reputation: 714

Change string to Areas.RetailShop.Models.FPSinformation in fun 

public List<CardGrouping> GetCardGrouping(List<Areas.RetailShop.Models.FPSinformation> queryable,
        Expression<Func<Areas.RetailShop.Models.FPSinformation, string>> groupingFunction,
        Func<Areas.RetailShop.Models.FPSinformation, int> sumFunction)

    {


        if (queryable.AsQueryable() != null)
        {

            var data = queryable.AsQueryable().GroupBy(groupingFunction).Where(x => x.Key != null).Select(x => new CardGrouping
            {
                Name = x.Key == null ? "" : x.Key.ToString(),
                Count = x.Sum(sumFunction)
            }).ToList();
            return data;
        }
        return null;
    }

Upvotes: 2

Jakub Lortz
Jakub Lortz

Reputation: 14894

There are 2 problems with this code.

First, to make it compile, the groupingFunction should be a Func<FPSinformation, int> - the type of input is not string, it's FPSinformation.

This change will make it compile, but the compiler will choose the Enumerable.GroupBy extension method. The Queryable.GroupBy requires an Expression<Func> parameter, not a Func - so it should be Expression<Func<FPSinformation, int>>

public List<CardGrouping> GetCardGrouping(IQueryable<FPSinformation> queryable, 
                             Expression<Func<FPSinformation, int>> groupingFunction)

You're grouping it by an int, so the .Where(x => x.Key != null) doesn't make sense - x.Key cannot be null.

Upvotes: 2

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