the problem with ON DELETE CASCADE isn't the CASCADE, it's the DELETE. Almost always, you want to to mark an entity disbled, not really DELETE it. If you want to DELETE it (for GDPR?) you should have something in place to fail your delete unless you've properly defined how to clean up danglig keys. (Perhaps what you need to do is delete the non-primary-key fields containing user data, but keep the row for relational integrity)
ON CASCADE DELETE is used for deleting logical sub-components (a row owned by another row) in a well normalized database -- it's for deleting your dadress book when you delete your account. It's not for deleting all your friends when your account is deleted.
> It's not for deleting all your friends when your account is deleted.
Very nice summary up until that point. But in a well normalized db the friends relationship (many-to-many) would be its own table. Friend relationships with the deleted user would be deleted, as they should be. Friends would not. (You still have time to edit for a better example.)
ON CASCADE DELETE is used for deleting logical sub-components (a row owned by another row) in a well normalized database -- it's for deleting your dadress book when you delete your account. It's not for deleting all your friends when your account is deleted.