compare two datatable and get differences

Question

I have two datatables and I want to get the difference between these two databases based on different columns and copy them to another datatable.

For example

datatable 1

Code	Name	Age	Money
123	User1	25	68000.00
456	User2	32	23000.00
963	User3	56	75000.00
852	User4	29	13000.00

datatable 2

Code	Name	Age	Money
963	User3	56	75000.00
456	User2	32	26000.58
123	User1	25	59000.63
852	User4	29	13000.00
741	UserN	22	15000.56

datatable result

Code	Name	Age	Money
456	User2	32	26000.58
123	User1	25	59000.63
741	UserN	22	15000.56

I use this code but it does not show the correct result

dtr = (from r in dt1.AsEnumerable()
                   where !dt2.AsEnumerable().Any(r2 => r[3].ToString().Trim() == r2[3].ToString().Trim())
                   select r).CopyToDataTable();

Answer 1

You can use Linq and Except to determine:

The set difference of two sets is defined as the members of the first set that don't appear in the second set.

In the example I am projecting the rows to anonymous types then doing the "except" set operation to obtain the result:

var dtrows = dt1.AsEnumerable().Select(rw => new { Code = rw[0], Name = rw[1], Age = rw[2], Money = rw[3] });
var dt2rows = dt2.AsEnumerable().Select(rw => new { Code = rw[0], Name = rw[1], Age = rw[2], Money = rw[3] });

dt2rows.Except(dtrows)