ok seems to be the right direction, but now I have another issue:
If I define ReferenceId as sure topic and instead of Labeltext '1'. It works great:
if(ReferenceId= '10660','1',ReferenceId) as ReferenceId_weekly,
So should be like this:
if(ReferenceId= '-',Labeltext,ReferenceId) as ReferenceId_weekly,
Two further questions:
1) How do I have to define Labeltext that it refers to the "Text" from the "Labels"-table? I got the error:
"Field not found - <Labeltext>"
2) How can I check how to define the '-'? It seems to be the wrong value, but my table shows me nothing in the cell and Qilk let me see this in the data model of the table.
Probably the '-' is for NULL values.
So you must ask yourself these questions: Is it normal to have null values for ReferenceId in my topics table ? And how i should manage them ?
You can handle null values with the isnull() function :
If (isnull(ReferenceId), 'Undefined ref', ReferenceId)
Otherwise : Understanding Join, Keep and Concatenate
Thank you so far. Very helpful!
I hoped to avoid using a join method because here I come into a new issue with 3 tables ( I am not aware how to deal with it), but I will try to get more information.
Sometimes the ReferenceId is not given and this is no issue, but I want to see then another field instead.
So I need an Outer Join to have all fields in the same Table and then I can work with the field when I call it in the same LOAD command.