User deletion failure

[a-deriabin]

When you try to delete a user, you'll get something like this:
org.postgresql.util.PSQLException: ERROR: update or delete on table "users" violates foreign key constraint "orders_client_id_fkey" on table "orders" Detail: Key (id)=(1) is still referenced from table "orders".

This is happening because foreign key in Orders table has NOT NULL constraint, but it's OnDelete action is No action. (I suggest to change it to CASCADE)