create table sotr(
  id int auto_increment primary key,
  obj int unique
  );
create table prod(
  id int auto_increment primary key,
  obj int unique
  );
create table obj(
  type_id int primary key,
  id int 
  );
insert obj values(1,1);

create trigger TR_sotr_BI
before insert on sotr
for each row begin 
  declare v_obj int;
  select id into v_obj from obj where type_id=1 for update;
  update obj set id=id+1;
  set new.obj=v_obj;
end
//
create trigger TR_prod_BI
before insert on prod
for each row begin 
  declare v_obj int;
  select id into v_obj from obj where type_id=1 for update;
  update obj set id=id+1;
  set new.obj=v_obj;
end
//

insert sotr () values (),();
insert prod () values ();
insert sotr () values ();
insert prod () values ();