Hi,

I've discovered a serious bug : those queries don't return the same result:

var groupedSumQueryable = from l in Query.All<MyEntity>().First().Lines
                                    group l by l.Rate.GetValueOrDefault() into g
                                    select new { Rate = g.Key, BaseAmount = g.Sum(l => l.Amount.GetValueOrDefault()) };

var groupedSumList = from l in Query.All<MyEntity>().First().Lines.ToList()
                               group l by l.Rate.GetValueOrDefault() into g
                               select new { Rate = g.Key, BaseAmount = g.Sum(l => l.Amount.GetValueOrDefault()) };

The only difference is the ToList converting the IQueryable to a simple list.

Sample project: [attachment=0:ie0iu504]DoTestSum.zip[/attachment:ie0iu504]

Regards,

Updated at 26.04.2010 15:31:58

Thanks for your input : but it's not the real problem here.

I will put below what I posted in the attached file:

First, I create some entities:

var helloWorld = new MyEntity
          {
            Text = "Hello World!",
            Lines =
            {
              new Line { Rate = 5.5M, Amount = 2M},
              new Line { Rate = 5.5M, Amount = 2M},
              new Line { Rate = 5.5M, Amount = 2M},
              new Line { Rate = 5.5M, Amount = 2M},
              new Line { Rate = 5.5M, Amount = 2M},
              new Line { Rate = 5.5M, Amount = 2M}
            }
          }

Then the first query (that could be quite logically included in a global ToList() as you suggest)

var groupedSumList = from l in Query.All<MyEntity>().First().Lines
                               group l by l.Rate.GetValueOrDefault() into g
                               select new { Rate = g.Key, BaseAmount = g.Sum(l => l.Amount.GetValueOrDefault()) };

          foreach (var groupedSum in groupedSumList)
          {
            Console.WriteLine(groupedSum.Rate + " Sum= " + groupedSum.BaseAmount);
          }

Output is: 5,500000000000 Sum= 33,000000000000

Then I execute the first query (indeed this will translate in sql like this : SELECT * FROM Lines WHERE ...)

var groupedSumQueryable = from l in Query.All<MyEntity>().First().Lines.ToList()
                                    group l by l.Rate.GetValueOrDefault() into g
                                    select new { Rate = g.Key, BaseAmount = g.Sum(l => l.Amount.GetValueOrDefault()) };

          foreach (var groupedSum in groupedSumQueryable)
          {
            Console.WriteLine(groupedSum.Rate + " Sum= " + groupedSum.BaseAmount);
          }

Output is : 5,500000000000 Sum= 12,000000000000

I will let you guess which one is correct ;)

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