Represents an 1 - N relationship where the source side of the relation is related to only one record in the target table.
Represents an M - N relationship where there exists a junction - or join - table that contains the association fields between the source and the target table.
Represents an N - 1 relationship where the target side of the relationship will have one or multiple records per each one in the source side.
Represents an 1 - 1 relationship where the source side of the relation is related to only one record in the target table and vice versa.
Implements cascading deletes for dependent associations.