Is the related record automatically deleted from the child table when the related key is deleted from the parent table?

Automatic deletion of related records from a child table when a key is deleted in the parent table depends on the database settings and the relationship schema (for example, cascade delete). In Java, this does not happen directly — this behavior is set at the database level through FOREIGN KEY constraints with the ON DELETE CASCADE option.

If such an option is not set, then deleting a record from the parent table will leave related records in the child table, which can lead to data integrity issues.

Example SQL for cascade delete:

ALTER TABLE child_table
ADD CONSTRAINT fk_parent
FOREIGN KEY (parent_id)
REFERENCES parent_table(id)
ON DELETE CASCADE;

In Java ORM (for example, Hibernate), cascade operations can be configured, but they only affect objects in memory and their save/delete operations, not the behavior of the database itself without the appropriate constraints.