Defining a column for join if it's not null

[ZimaBlue]

I have table_1:

month_start_date	partner	campaign
1-10-2021	partner1	test1
1-5-2021	partner2	test2

and table_2:

month_start_date	partner	campaign	money
1-10-2021	partner1	test1	100
1-3-2021	partner5	-	500
1-5-2021	partner2	test2	300
1-11-2021	partner10	-	500

What I expect:

- the amount from the money column should be joined to table_1 to the partner->campaign correspondences for those rows where both fields are filled in table_2.

- For lines in which in table_2 campaign = "-" I want to see money joined simply by the partner field. I expected that due to the same column name, qlik would be able to figure it out, but it doesn't seem to be able to do that.

How do I explicitly indicate what to do in this case?

Now i use just:

Left Join (table_1)
load [month_start_date], [partner], [campaign], [money] resident table_2;

[ZimaBlue · Accepted solution]

I found the following solution:

for all empty capmaign in table_1, I assigned the value "-", so the script finds "-" as the match for join.