Hi, i did a backup and recovery plan on one of my client database, cuse he did not have any. He lost 2 weeks of data because of this.

And i found something that give me chils!
They dont have any primary, foreign key, check constraints!!!!
They have about 100 tables.
I want to make them use constraints, but they told me they did not have any data lost because of not having constarints. But still why use a expensive database and not using basic security?

They lost already time because of bad backup and recovery plan i dont want to see them lose data because someone delete a parent record and letting the child record in the database.

Do you have suggestion on arguments to give on why use constraints?