Duplicates entries on OneToMany Mapping

I’m creating a user and role association with ManyToOne & OneToMany mappings. I’m executing this thru a rest API to persist data. The issue is that when I run API multiple times, the same role is created multiple times in role table. Below the details. Please help.

Database used is PostGreSqL



Issue here - same role is created multiple times, which should not be ideally.


Hibernate is just doing what your code is instructing it to. You always save a new Role on each call. If you want to update an existing Role, you will have to implement that by looking up the Role by e.g. name and if that exists, update that, otherwise create a new one. Beware that it is still possible to create duplicate Roles though. If you want to avoid this, you should create a unique constraint on e.g. name so that the database makes sure the duplicate can never be inserted.