select all rows that count of quantity fields least equal- Entity framework

Question

I have Table like ProductInventory , In that I have some product with quantity .

I want select all rows where The least of a field equals to my input(number) .

I try with this :

List<product> Products = new List<product> { 
    new product{Id=1,Name="A",Quantity=1},
    new product{Id=1,Name="A",Quantity=2},
    new product{Id=1,Name="A",Quantity=3},
    new product{Id=1,Name="B",Quantity=4},
    new product{Id=1,Name="B",Quantity=7}
};

var result = Products
    .AsEnumerable()
    .GroupBy(r => r.Name)
    .Where(g => (int)g.Sum(r =>r.Quantity)<= 4)
    .ToList();

but it causes a return zero.

example:

your question not clear ? what did you trying ? if yes share code — Nazmul Hasan, May 09 '16 at 08:54
I dont know how can I do this and I dont any trying becuase I dont have any idea — Uthman Rahimi, May 09 '16 at 08:55
`I searched on google but cant find any result.` I highly doubt that ... try `LINQ where clause` and hit "I'm feeling Lucky" — Manfred Radlwimmer, May 09 '16 at 08:56
@ManfredRadlwimmer My english is not very well and I dont know what should be search — Uthman Rahimi, May 09 '16 at 08:57
Read http://stackoverflow.com/questions/7325278/group-by-in-linq — Paul Zahra, May 09 '16 at 10:10

reza.cse08 · Answer 1 · 2016-05-09T11:37:43.943

2

I don't know is it possible in linq or not. But you can try this.

var result = Products.AsEnumerable().Where(g => g.Name == "A").ToList();

int userInput =4;
var total = 0;
var selectList = new List<product>();
for (int i = 0; i < result.Count; i++)
{
   for (int j = i; j < result.Count; j++)
    {
      if (total + result[j].Quantity <= userInput)
      {
         total += result[j].Quantity;
         selectList.Add(result[j]);
       }
     }
     if (total == userInput)
       break;
     else
     {
        total = 0;
        selectList = new List<product>();
      }
}
if(userInput!=total)
 selectList = new List<product>();

edited May 09 '16 at 11:37

answered May 09 '16 at 09:02

reza.cse08

5,938
48
39

1

Please check. you are find an item with name="A" and quantity=4. but there is no item with that condition in your list. – reza.cse08 May 09 '16 at 09:13
Ok , I know , but in fiddel that retuen two recirds that sum of `quantity = 4` , – Uthman Rahimi May 09 '16 at 09:15
if user input `4` this should return all rows witch sum of `quantity = 4` – Uthman Rahimi May 09 '16 at 09:15
ok my dear , its wrong , see https://dotnetfiddle.net/ad47pX , sorry dont try againg – Uthman Rahimi May 09 '16 at 11:31
there is no item that's quantity will be 6 from your sample data. – reza.cse08 May 09 '16 at 11:34
I have `12` items as `A` – Uthman Rahimi May 09 '16 at 11:35
Let us [continue this discussion in chat](http://chat.stackoverflow.com/rooms/111421/discussion-between-shamim-reza-and-uthman-rahimi). – reza.cse08 May 09 '16 at 11:38

Manfred Radlwimmer · Answer 2 · 2016-05-09T09:51:36.217

1

With that latest update, I think I finally understand what you are trying to do.

This won't work however, because you cant build the sum of booleans.

var result = Products
    .AsEnumerable()
    .GroupBy(r => r.Name)
    .Where(g => g.Sum(r =>r.Quantity== 4))
    .ToList();

What you actually want is

var result = Products
    .GroupBy(r => r.Name)
    .Where(g => g.Sum(r =>r.Quantity) >= 4) //or == 4 or whatever
    .ToList();

edited May 09 '16 at 09:51

answered May 09 '16 at 09:38

Manfred Radlwimmer

13,257
13
53
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your code is ok , thanks , and i change code in new update , I should try with your code – Uthman Rahimi May 09 '16 at 09:43

select all rows that count of quantity fields least equal- Entity framework

2 Answers2