Changing the source table structure

We've seen how the QlikView engine works and the importance of having a data model design that fully takes advantage of QlikView's associative algorithms. So, the first section of this chapter deals with transforming source tables to make them adequate for our data model. The different structure transformations we'll make are:

• "Cleansing" a dirty table

• Converting a Crosstable to a standard table

• Using hierarchy tables

• Loading generic tables

"Cleansing" a dirty table

As we've said before, it's not that uncommon for business users to require consolidated information from all sorts of different sources: the CRM, the company's Data Warehouse, Excel tables, Legacy systems, and so on. In these scenarios, the developer commonly faces the challenge of adapting a user file (Excel, CSV, TXT) that has either a non-standard structure or contains "dirty" data which needs to be removed, such as report headers or subtotal lines, and sometimes both.

Fortunately for us, QlikView...