I am having an issue with an application i inherited. I am still a learner in qlikview. The application is developed already but i am not able to understand why the previous developer used a function in the script. there are basically three tables. two tables have a common key but one does not have any common key. the developer used interval match function and left joined it to one of the table with common key.
here is the script
LOAD [Campaign id],
FROM Campaign-Source-Data.xlsx (ooxml, embedded labels, table is campaign);
1 As Email,
FROM Campaign-Source-Data.xlsx (ooxml, embedded labels, table is clicks);
It would be even tough for people here to say why it was done so without knowing your data and business logic. Ideally, when you take over a project/dashboard the KT would be the key. If you were not KTed properly then it's a mess. At this point, I can ask you to read about the business logic and data structure first and then may be learn qv: IntervalMatch ‒ QlikView and Join ‒ QlikView from help/manuals.
The code is is associating a campaign (with a start and end date) with the email information (with a sent date in the interval between the campaign start and end date). But as Tresesco said, its hard to be more specific than that.