You should be aware that the problem always lies in removing the parent app, record, or whatever thing that has children, not vice versa, and to solve this problem, you should remove the child before removing the parent. It's not related to Programming only, but it's a global problem that exists in all Tech. fields especially the Databases so, let me explain how to deal with this scenario in Laravel

Let's consider that every user has only one car. The database schema is gonna be: