- mappedBy has to be specified on the inversed side of a (bidirectional) association
- inversedBy has to be specified on the owning side of a (bidirectional) association
from doctrine documentation:
- ManyToOne is always the owning side of a bidirectional assocation.
- OneToMany is always the inverse side of a bidirectional assocation.
- The owning side of a OneToOne assocation is the entity with the table containing the foreign key.