How to calculate sum of a DataTable's Column in LINQ (to Dataset)?

Question

I'm just started to read up on LINQ and I want to start incorporating it into my code. I know how to compute the sum of a DataTable's column by either "Foreach"-ing through the rows or by doing a compute.sum on the specific column. How do I do the equivalent with LINQ to DataSet?

Solution 1

If untyped (replace int with the correct data type):

 var sum = table.AsEnumerable().Sum(x=>x.Field<int>(3));

or:

 var sum = table.AsEnumerable().Sum(x=>x.Field<int>("SomeProperty"));

If typed:

 var sum = table.Sum(x=>x.SomeProperty);

Solution 2

If you data field is integer

var sum = TableData.Sum(x => x.FieldName);

If your data field is string then you need to parse it as integer

var sum = TableData.Sum(x => Int32.Parse(x.FieldName));

If your data field is string and you want to store result as string

var sum = TableData.Sum(x => Int32.Parse(x.FieldName)).ToString();

Comments

[Viktor Vix Jančík]

Note that you need the System.Data.DataSetExtensions Assembly for the above to work.

[JohnB]

@kervin: also, you need to make sure this is on top of your code file: using System.Linq;

[Shaiju T]

just to understand and if i am correct, when you say typed and un-typed does it mean typed view and un-typed view in asp mvc , i mean the ViewModel class that we create ?