I have just started working with EJBs, so I don't know much about them, but doing a test a faced the following situation:
I have an entity named Product, that has an N:N relationship with one called Sector
in other words a Product can be sold in many Sectors and a Sector sells many Products
In my Product entity I have a list of Sectors, in a @OneToMany relationship.
And in my database I have 3 tables: Products, Sectors, and ProductSectors.
All the data from this relationship is persisted in the ProductSectors table
Well then, on to the issue: I have a product with 3 sectors in it's list, all already persisted in the database, now when I remove one sector from my list, and merge my Product, I saw that hibernate executed 3 queries
So as you can see, all the records were deleted, and then he inserted the other 2 again, is this behavior normal? Is there any way for me to change it via configuration or something else? So it will just delete the one Sector, with a single query?