Sum of SQL table rows with LINQ ?

Question

There is a table in a SQL database like below :

SampleTable :

-----------------------
 id | number | price 
-----------------------
 1  |   3    | 300
 2  |   1    | 200
 3  |   5    | 100
 4  |   10   | 10
 5  |   30   | 30
 6  |   1    | 500
-----------------------

I wanna calculate total price like below :

in each row => var SumOfEachRow = number * price;
Total Price = sum of SumOfEachRow;

Thus the Total Price would be 3100.

Now , I wanna calculate it with LINQ. e.g :

int TotalPrice = from q in SampleTable
                 select new
                 {
                    TotalPrice = q.number * q.price 
                 }.Sum();

the upside code returns the wrong result !!! Could you please guide me ? Thanks.

Answer 1

Try:

decimal TotalPrice = SampleTable.Sum(q => q.number * q.price);

Answer 2

try this

  var TotalPrice = from q in SampleTable.AsEnumerable()
                         let y = Convert.ToInt32(q["number"]) * Convert.ToInt32(q["price"])
                         select y;

      int totalPrice =  TotalPrice.Sum();