Join data table activity - left Join not working as expected

[ppr (Peter Preuss)]

we do see that 123 occurs twice. So the nature of join will create follwoing:

take first 123 from dt1 join it with

• 123-pen from dt2
• 123-pen from dt2

take the second 123 from dt1 join it with

• 123-pen from dt2
• 123-pen from dt2

thats why th 4 rows are found.

In such cases removing duplicates e.g in dt2 or custom join logic can help. here is just to rule when left 123 is picked up by which rule the both 123 rows from dt2 are to select for the pairing.