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.
This exercise is part of the course
Joining Data with dplyr
Exercise 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
Hands-on interactive exercise
Have a go at this exercise by completing this sample 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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