Thread: Re: [BUGS] bug in "fetch" command?

Can someone comment on this?  Is is a bug?


> ============================================================================
>                         POSTGRESQL BUG REPORT TEMPLATE
> ============================================================================
>
>
> Your name        : Sergey E. Levov
> Your email address    : serg@informika.ru
>
>
> System Configuration
> ---------------------
>   Architecture (example: Intel Pentium)      : Intel Pentium Pro
>
>   Operating System (example: Linux 2.0.26 ELF)     : FreeBSD 2.2.5
>
>   PostgreSQL version (example: PostgreSQL-6.3.2)  :   PostgreSQL-6.3.2
>
>   Compiler used (example:  gcc 2.7.2)        : gcc 2.7.2.1
>
>
> Please enter a FULL description of your problem:
> ------------------------------------------------
> When I declare cursor for select statement without "ORDER BY" clause
> ( select * from <tablename> ), and then attempt to fetch record after
> last record in table, or even just give "fetch all" command,
> all the following "fetch" commands, regardless direction, will return
> an empty result sets.
> If "SELECT" statement has "ORDER BY" clause, all works well.
>
>
>
> Please describe a way to repeat the problem.   Please try to provide a
> concise reproducible example, if at all possible:
> ----------------------------------------------------------------------
> Try the following sequence of SQL operators:
>
> begin
> declare mycurs cursor for select * from pg_user
> fetch all in mycurs             - OK
> fetch backward all in mycurs    - fails
> move backward all in mycurs
> fetch all in mycurs        - fails
> close mycurs
>
> declare mycurs cursor for select * from pg_user order by usename
> fetch all in mycurs        - OK
> fetch backward all in mycurs    - OK
> move backward all in mycurs
> fetch all in mycurs        - OK
>
>
> Regards,
> Sergey Levov (serg@informika.ru)
>
>
>
>


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> Can someone comment on this?  Is is a bug?

I was a bit suprised to see this behavior. I am guessing that it is a
bug. Does anyone else think so? I last tested and noticed this a week or
two ago when writing docs...

                  - Tom

> > Please enter a FULL description of your problem:
> > ------------------------------------------------
> > When I declare cursor for select statement without "ORDER BY" clause
> > ( select * from <tablename> ), and then attempt to fetch record
> > after last record in table, or even just give "fetch all" command,
> > all the following "fetch" commands, regardless direction, will
> > return an empty result sets.
> > If "SELECT" statement has "ORDER BY" clause, all works well.
> > Try the following sequence of SQL operators:
> >
> > begin
> > declare mycurs cursor for select * from pg_user
> > fetch all in mycurs             - OK
> > fetch backward all in mycurs  - fails
> > move backward all in mycurs
> > fetch all in mycurs           - fails
> > close mycurs
> >
> > declare mycurs cursor for select * from pg_user order by usename
> > fetch all in mycurs           - OK
> > fetch backward all in mycurs  - OK
> > move backward all in mycurs
> > fetch all in mycurs           - OK