How to compare and find not matching item in two data tables?

[ppr (Peter Preuss)]

have a look here as an introduction to the topic:

Full Join - compare datatable 1 with datatable 2 - return matching and not matching items

@Karan28 the Join activity did a good job for doing the full Join [grafik] Linq was helpfully for bring it into the target structure: (From dj In dtJoin.AsEnumerable Let c1 = If(String.IsNullOrWhiteSpace(dj("Column1").toString), dj("Column1_1"),dj("Column1")) Order By c1 Let ra= New Object(){c1,dj("Column2"), dj("Column2_1")} Select dtResult.Rows.Add(ra)).CopyToDataTable [grafik] Find demo XAML here: FullJoin_TotalColResult_JoinActivity.xaml (12.2 KB)

also find some starter help here:
Find_Common_NonCommon_By1Col.xaml (12.3 KB)

another option is to work with the dataset operation

How to remove common rows from data tables

@EMREUYSAL find starter help here: DataTable_SetOperations.xaml (8.9 KB) was done with the set operations Intersect And Except: Another techniques is to do it with Any and denied Any in combination sequenceEqual (have also a look here on the use of sequenceequal - [HowTo] - Find Duplicate / NonDuplicate rows - checking all columns - without explicit listing the colnames/index ) to safe it up it is recommended to do the empty result check similar as below [grafik]