CODEWITHSUNDEEP
c#asp.netlinqdatetimegroup-by
User987
User987

Reputation: 3823

LINQ group by datetime and sum

I have a List of orders purchased on specific date. I need to group them all into one date ( purchases made on same day) and then sum them.. I made a class which looks like this: 

 public class StoreAnalyticOrders
    {
        public DateTime OrderDate { get; set; }
        public float AmountPaid { get; set; }

    }

And then the I fill the list which is called "GraphList" with results...

The LINQ that I tried to perform what I just described up there is:

  var result = GraphList
      .GroupBy(l => l.OrderDate)
      .Select(cl => new StoreAnalyticOrders
      {
          AmountPaid = cl.Sum(c => c.AmountPaid),
      }).ToList();

But for some reason the dates are in bad format (they are lost) and they show up like this:

1/1/0001 12:00:00 AM

and this is the previous format of the Order date property:

11/21/2016 6:05:32 AM

What am I doing wrong here?

Edit: @Ivan Stoev is this what you ment: 

  var result = GraphList
                    .GroupBy(l => l.OrderDate.Date)
                     .Select(cl => new StoreAnalyticOrders
                     {
                         OrderDate = cl.Key,
                         AmountPaid = cl.Sum(c => c.AmountPaid)
                     }).ToList();

Upvotes: 0

Views: 1203

Answers (1)

Ashkan Mobayen Khiabani
Ashkan Mobayen Khiabani

Reputation: 34150

You can not use make changes to datetime in a linq to entities query, and you should use DbFunctions:

GraphList.GroupBy(gl => DbFunctions.TruncateTime((DateTime)gl.Datetime)).
Select(gl=> new{
    Date = DbFunctions.TruncateTime((DateTime)gl.FirstOrDefault().Datetime),
    TotalAmountPaid = gl.Sum(x=> x.AmountPaid)
}).ToList();

Upvotes: 1

Related Questions