Re: Getting the results columns before execution - Mailing list pgsql-hackers

From Darko Prenosil
Subject Re: Getting the results columns before execution
Date
Msg-id 200401191548.16865.darko.prenosil@finteh.hr
Whole thread Raw
In response to Getting the results columns before execution  (Shachar Shemesh <psql@shemesh.biz>)
List pgsql-hackers
On Monday 19 January 2004 15:13, Shachar Shemesh wrote:
> Hi all,
>
>  From the OLE DB manual:
> > The consumer can also get information about the columns of the rowset
> > by calling IColumnsInfo::GetColumnInfo, which all providers must
> > support, or IColumnsRowset::GetColumnsRowset, which providers may
> > support, on the command.
> >
> > Before calling GetColumnInfo or GetColumnsRowset, the consumer must
> > set the command text and, if the provider supports command
> > preparation, prepare the command object.
>
> The problem - it appears there is no requirement to execute the command
> before asking about the rowset returned. Only setting the actual command
> and preparing it. This is a problem, as merely preparing a command is
> not enough to get the returned rows information.
>
> I'm wondering whether anyone on this list(s) have an idea how to solve
> this? I can start the command in a cursor, and not retrieve information
> until requested. I can also execute the command with "where 0" appended
> to it. Neither solutions seem very practical or good performance wise.
>
>                 Shachar

LIMIT 0 will do ?
I do it often when I need to know structure of the result without returning 
any rows.

Regards !


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