st 25. 1. 2023 v 17:22 odesÃlatel songjinzhou <2903807...@qq.com> napsal:
> > >Hi > > >st 25. 1. 2023 v 16:39 odesÃlatel songjinzhou <2903807...@qq.com> > napsal: Hello, my personal understanding is that you can use multiple > iterative controls (as a merge) in a fo loop, otherwise we can only > separate these iterative controls, but in fact, they may do the same thing. > > >1. please, don't use top posting in this mailing list > https://en.wikipedia.org/wiki/Posting_styl > > >2. I understand the functionality, but I don't think there is a real > necessity to support this functionality. Not in this static form, and just > for integer type. > > >Postgres has a nice generic type "multirange". I can imagine some > iterator over the value of multirange, but I cannot imagine the necessity > of a richer iterator over just integer range. So the question is, what is > the real possible use case of this proposed functionality? > > 1. I'm very sorry that my personal negligence has caused obstacles to your > reading. Thank you for your reminding. > 2. With regard to the use of this function, my understanding is relatively > simple: there are many for loops that may do the same things. We can reduce > our sql redundancy by merging iterative control; It is also more convenient > to understand and read logically. > > As follows, we can only repeat the for statement before we use such SQL: > > begin > for i in 10..20 loop > raise notice '%', i; -- Things to do > end loop; > > for i in 100 .. 200 by 10 loop > raise notice '%', i; -- Things to do > end loop; > end; > > But now we can simplify it as follows: > > begin > for i in 10..20, 100 .. 200 by 10 loop > raise notice '%', i; -- Things to do > end loop; > end; > > Although we can only use integer iterative control here, this is just a > horizontal expansion of the previous logic. Thank you very much for your > reply. I am very grateful! > > Unfortunately, this is not a real use case - this is not an example from the real world. Regards Pavel > --- > > songjinzhou(2903807...@qq.com) > >
