Multi-column keys
Two new datasets are available in your R session:
subjects: contains the subject each student is taking each semester this yearlocations: contains the room allocations for each subject
Your goal is to build a new data.table with the locations of each subject for each student.
Este exercício faz parte do curso
Joining Data with data.table in R
Exercício interativo prático
Experimente este exercício completando este código de exemplo.
# Right join
subjects[___]