Case and the decision tree algorithm

When it is needed to use case and nested table in the decision tree algorithm?.
Is only useful when you need to relate tables but is not the same concept
that in Association rules, where case is the entity that we want to analyze.
(i.e. the Basket in the market basket analysis)

Thanks in advance.
Joe.

 

The idea of the nested table is to group together a set of attributes from
the same domain that are associated with a case. This concept is applicable
across all algorithms.

For example, you might have demographic information about customers like
age, marital status, income as well as their favorite TV shows and you want
to predict their gender. This would be a good candidate for a decision tree
model with "Favorite TV Shows" as a nested table. If you didn't have nested
tables, you would need to have a boolean case-level column for each show -
"Likes Friends", "Likes Oprah", "Likes Smallville" and so forth.