Re: using placeholders in psql

On Sat, 5 May 2001, Peter Eisentraut wrote:

> Oleg Bartunov writes:
>
> > just an idea to use placeholders (?) in psql.
> > It would be useful for interactive work and debuging.
> > We already have powerful features in psql but sometimes
> > we need more. If user enter select string with placeholder,
> > he may get prompt to input something for arg1, then for arg2...
>
> You can simulate this:
>
> $ cat test.sql
> \echo -n 'Enter something: '
> \set val1 `read && echo $REPLY`
>
> \echo -n 'And something else: '
> \set val2 `read && echo $REPLY`
>
> select :val1, :val2;
>
> $ psql -f test.sql
> Enter something: 55<enter>
> And something else: 77<enter>
> ?column? | ?column?
> ----------+----------
> 55 | 77
> (1 row)
>
> Does this work for your application?

Thanks for the tip. Sure, it works.
But my thought was about intrinsic feature of psql.
Most time I use psql is for interactive debugging. With history
feature it would be very convenient.

>
> The question marks pose too much of an incompatibility problem. The :var
> notation was already much disputed, even though it's kind of standard.
>

question mark is just borrowed from DBI syntax, no problem with
:var

>

Regards,
Oleg
_____________________________________________________________
Oleg Bartunov, sci.researcher, hostmaster of AstroNet,
Sternberg Astronomical Institute, Moscow University (Russia)
Internet: oleg(at)sai(dot)msu(dot)su, http://www.sai.msu.su/~megera/
phone: +007(095)939-16-83, +007(095)939-23-83