On Fri, Apr 24, 2020 at 12:24 PM Pavel Stehule <pavel.steh...@gmail.com> wrote: > > Hi > > plpgsql generate lot of auto variables - FOUND, SQLERRM, cycle's control > variable, TG_WHEN, TG_OP, .. > > Currently these variables are not protected, what can be source of problems, > mainly for not experienced users. I propose mark these variables as constant. >
+1 for general idea. > -- today > postgres=# do $$ begin for i in 1..10 loop raise notice 'i=%', i; i := 20; > end loop; end; $$; > NOTICE: i=1 > NOTICE: i=2 > NOTICE: i=3 > NOTICE: i=4 > NOTICE: i=5 > NOTICE: i=6 > NOTICE: i=7 > NOTICE: i=8 > NOTICE: i=9 > NOTICE: i=10 > DO > > -- after patch > postgres=# do $$ begin for i in 1..10 loop raise notice 'i=%', i; i := 20; > end loop; end; $$; > ERROR: variable "i" is declared CONSTANT CONSTANT looks odd in this context since i's value changes. But you already have a proposal to change that. > > p.s. this is simple implementation - just for function demo. Maybe can be > better to introduce new plpgsql_variable's flag like is_protected or similar > than using isconst. Yes, I think that will help. In this case PL/SQL says that "i" can not be used as an assignment target. That's not very clear but something on those lines will help. -- Best Wishes, Ashutosh Bapat
