Обсуждение: Refer to n'th field of a table?

Hi,

Sorry for asking the dynamic command question without thoroughly reading the
documentation first.
Thanks a lot for your reply, Richard. ;-)

Now this may be a naive SQL question:
Is there any way to refer to the nth field of a table? For example, when I
already know the schema of
a table( I know it's first field is integer, second and third are text), but
don't know the field names,
is there any way to simply refer to the field by it's position in the table
rather than it's field name?
Also the same question goes with a record(row)?

Many thanks,

Wei Wang

On Thursday 19 February 2004 19:22, Wei Wang wrote:
> Hi,
>
> Sorry for asking the dynamic command question without thoroughly reading
> the documentation first.
> Thanks a lot for your reply, Richard. ;-)
>
> Now this may be a naive SQL question:
> Is there any way to refer to the nth field of a table? For example, when I
> already know the schema of
> a table( I know it's first field is integer, second and third are text),
> but don't know the field names,
> is there any way to simply refer to the field by it's position in the table
> rather than it's field name?

It is possible if you use libpq i.e. C API to access database. You can access
the field value either by name or number.

> Also the same question goes with a record(row)?

Yes. With C API it is possible.

 Check
http://www.postgresql.org/docs/7.4/static/libpq-exec.html#LIBPQ-EXEC-SELECT-INFO

 Shridhar