Loop Block with execution doesn't persist

Question

I need to iterate over a result set and update records from the data. I am using an anonymous block but the information does not persist.

Like this...

do $$ 
declare dados Record; 
begin 
   for dados in 
        select 
           vd."Id"
        from "Vendas" vd 
           inner join "ItensVendas" iv on iv."VendaId" = vd."Id" 
        where vd."Especie" = 'NFE' and coalesce(vd."ClienteId", 0) = 0 and iv."CodCFOP" in (5949, 5927) 
        group by vd."ChaveNFE", vd."Id", vd."DataCadastro" 
   loop 
        execute format('update "Vendas" set "EhConsumoProprio" = true where "Id" = %L', dados."Id"); 
   end loop; 
end $$; 

And again...

do $$
declare dados Record;
declare cmd varchar(300);
begin
    for dados in 
        select
            vd."ChaveNFE",
            vd."Id",
            vd."DataCadastro"
        from
            "Vendas" vd
        inner join "ItensVendas" iv on
            iv."VendaId" = vd."Id"
        where
            vd."Especie" = 'NFE'
            and coalesce(vd."ClienteId",0)= 0
            and iv."CodCFOP" in (5949, 5927)
        group by vd."ChaveNFE",
                 vd."Id",
                 vd."DataCadastro" 
    loop
        raise notice '%',dados."Id";
        update "Vendas" set "EhConsumoProprio"=true where "Id"=dados."Id"; -- It don't persists
        cmd := format('update "Vendas" set "EhConsumoProprio"=true where "Id"=%L', dados."Id");
        raise notice '%', cmd;
            execute cmd; -- It don't persists
    end loop;
end $$;

Answer 1

IMHO just a single UPDATE can solve your issue. Something like this:

UPDATE "Vendas"
   SET "EhConsumoProprio" = TRUE
  FROM "ItensVendas"
 WHERE "ItensVendas"."VendaId" = "Vendas"."Id"
   AND "Vendas"."Especie" = 'NFE'
   AND "Vendas"."ClienteId" IS NOT DISTINCT FROM 0
   AND "ItensVendas"."CodCFOP" IN (5949, 5927);