Joining themes to their grandchildren
We can go a step further than looking at themes and their children. Some themes actually have grandchildren: their children's children.
Here, we can inner join themes
to a filtered version of itself again to establish a connection between our last join's children and their children.
Cet exercice fait partie du cours
Joining Data with dplyr
Instructions
- Use another inner join to combine
themes
again with itself.- Be sure to use the suffixes
"_parent"
and"_grandchild"
so the columns in the resulting table are clear. - Update the
by
argument to specify the correct columns to join on. If you're unsure of what columns to join on, it might help to look at the result of the first join to get a feel for it.
- Be sure to use the suffixes
Exercice interactif pratique
Essayez cet exercice en complétant cet exemple de code.
# Join themes to itself again to find the grandchild relationships
themes %>%
inner_join(themes, by = c("id" = "parent_id"), suffix = c("_parent", "_child")) %>%
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