Linq Query for comparing Two DataTables

I have two data tables dt1 and dt2
i want to compare 2 data tables using linq query if they are matched or d2 is empty if True then I will proceed to the next Step else if they are different then Bot should consider d2 one and edit d1 row to replace these different row with d2 one.

what u mean by d2 and d1 here?

dt1 and dt2 the two datatables