text: 
    CREATE OR REPLACE TRIGGER "TRG_KEY_ANNOTATIONS" 
      BEFORE INSERT OR UPDATE ON annotations
      FOR EACH ROW
      BEGIN
          if :new.ANNOTATION_ID is null then
          select sq_annotation_id.nextval into :new.ANNOTATION_ID from dual;
          end if;
      end;
  
  ALTER TRIGGER "TRG_KEY_ANNOTATIONS" ENABLE