Question

I have two datatables with same identity column. I want to update one column value in one table with other column value in another table. For example:

These are the two tables:

Table1:

       ID         Name           Amount
     ------      -------        ---------
        1          AA             0
        2          BB             0
        3          CC             0

Table2:

       ID        Amount
     ------    ---------
        1        5000
        2        6000
        3        7000            

My desired datatable should like this:

DesiredTable:

       ID         Name           Amount
     ------      -------        ---------
        1          AA             5000
        2          BB             6000
        3          CC             7000

I don’t want to use for loop. How to achieve this result using LINQ?

Answer 1

Here Consider Table1 as ‘DTTable1’ and Table2 as DTTable2:

DTTable1.AsEnumerable().Join(DTTable2.AsEnumerable(), 
                     dt1_Row => dt1_Row.ItemArray[0],
                     dt2_Row => dt2_Row.ItemArray[0],
                     (dt1_Row, dt2_Row) => new { dt1_Row, dt2_Row }).ToList() 
                     .ForEach(o => o.dt1_Row.SetField(2, o.dt2_Row.ItemArray[1]));