Обсуждение: Query Problem!!

I have PostgreSQL v7.02 in RedHat 6.2;

I have problem with is Query:
select name, 'user' as class from smuser union select name, 'group' as clas=
s from smgroup order by class;

sentence problem is:{ order by class} !!!!=20

thank you,=20
Christian Gonzalez

On Mon, 8 Jan 2001 15:50:42 -0400, <christiangda@cantv.net> wrote:
> I have PostgreSQL v7.02 in RedHat 6.2;
>
> I have problem with is Query:
> select name, 'user' as class from smuser union select name, 'group' as class from smgroup order by class;
>
> sentence problem is:{ order by class} !!!!
>
> thank you,
> Christian Gonzalez

Hi. This is because ``class'' is one of the reserved keywords of
PostgreSQL.  You can avoid this problem by using quoted identifiers
like

   select name, 'user' as "class" from smuser ...,

or simply rename the attribute.

-----
Yoshihiko Ichikawa
Department of Information Sciences, Ochanomizu University
Phone: +81-3-5978-5708; Fax:   +81-3-5978-5705
E-mail: ichikawa@is.ocha.ac.jp

<christiangda@cantv.net> writes:
> <DIV><FONT face=3DArial size=3D2>I have PostgreSQL v7.02 in RedHat 6.2;</FO=
NT> </DIV>
> <DIV><FONT face=3DArial size=3D2></FONT> </DIV>
> <DIV><FONT face=3DArial size=3D2>I have problem with is Query:</FONT></DIV>
> <DIV><FONT face=3DArial size=3D2>select name, 'user' as class from smuser u=
> nion=20
> select name, 'group' as class from smgroup order by class;</FONT></DIV>
> <DIV><FONT face=3DArial size=3D2></FONT> </DIV>

Please turn off HTML mail :-(

The problem is with the nonspecific-type literals; 7.0 won't resolve
those to a particular datatype by itself, so it doesn't know how to sort
them.  Try

select name, 'user'::text as class from smuser
union
select name, 'group'::text as class from smgroup
order by class;

            regards, tom lane